diff --git a/PhoneToolMX.Models/AllowNullAttribute.cs b/PhoneToolMX.Models/AllowNullAttribute.cs
new file mode 100644
index 0000000..5181d0d
--- /dev/null
+++ b/PhoneToolMX.Models/AllowNullAttribute.cs
@@ -0,0 +1,7 @@
+namespace PhoneToolMX.Models
+{
+    public class AllowNullAttribute : Attribute
+    {
+        
+    }
+}
diff --git a/PhoneToolMX.Models/Data/PTMXContext.cs b/PhoneToolMX.Models/Data/PTMXContext.cs
index c7401b9..8bcea1b 100644
--- a/PhoneToolMX.Models/Data/PTMXContext.cs
+++ b/PhoneToolMX.Models/Data/PTMXContext.cs
@@ -38,6 +38,20 @@ namespace PhoneToolMX.Data {
             var entry = await AddAsync(entity);
             return entry;
         }
+        
+        /// <summary>
+        /// Gets a DbSet with all required relationships
+        /// </summary>
+        /// <typeparam name="TEntity">IOwnedModel</typeparam>
+        /// <returns>DbSet&lt;TEntity&gt;</returns>
+        private IQueryable<TEntity> GetFullSet<TEntity>() where TEntity: class, IModel
+        {
+            var set = Set<TEntity>().AsQueryable();
+            return typeof(TEntity).GetProperties()
+                .Where(p => p.GetCustomAttributes(typeof(AlwaysIncludeAttribute), true)
+                    .Length != 0)
+                .Aggregate(set, (current, prop) => current.Include(prop.Name));
+        }
 
         /// <summary>
         /// Gets all entities of a certain model owned by the <see cref="User"/>.
@@ -48,14 +62,11 @@ namespace PhoneToolMX.Data {
         public ICollection<TEntity> GetOwned<TEntity>(User owner) where TEntity : class, IOwnedModel
         {
             if (owner == null) return null;
-            var entity = Set<TEntity>().Where(x => x.Owners.Any(o => o.Id == owner.Id));
+            var entity = GetFullSet<TEntity>().Where(x => x.Owners.Any(o => o.Id == owner.Id));
             // eager load all w/ AlwaysInclude
-            entity = typeof(TEntity).GetProperties()
-                .Where(p => p.GetCustomAttributes(typeof(AlwaysIncludeAttribute), true)
-                    .Length != 0)
-                .Aggregate(entity, (current, prop) => current.Include(prop.Name));
             return entity.ToList();
         }
+        
 
         /// <summary>
         /// Gets a model entity by its Id
@@ -67,7 +78,7 @@ namespace PhoneToolMX.Data {
         /// </remarks>
         public TEntity GetEntityById<TEntity>(int? id) where TEntity : class, IModel
         {
-            return id == null ? null : Set<TEntity>().FirstOrDefault(o => o.Id == id);
+            return id == null ? null : GetFullSet<TEntity>().FirstOrDefault(o => o.Id == id);
         }
         
         #endregion
@@ -79,6 +90,7 @@ namespace PhoneToolMX.Data {
             ext.HasKey(x => x.Id);
             ext.Property(x => x.Id).UseIdentityColumn();
             ext.Property(x => x.ExtId).HasComputedColumnSql("\"Id\" + 1000", stored: true);
+            // Randomly generates a 24-char password
             ext
                 .Property(p => p.Password)
                 .HasDefaultValueSql("encode(gen_random_bytes(18), 'base64')");
@@ -89,7 +101,7 @@ namespace PhoneToolMX.Data {
                 .WithMany(x => x.Phones);
             phone.HasKey(p => p.Id);
             phone.Property(p => p.Id).UseIdentityColumn();
-            // Randomly generates a 24-char password
+            phone.HasOne(p => p.PrimaryExtension).WithMany();
 
             // Wallpapers, ringtones, etc
             var cd = modelBuilder.Entity<CustomData>();
diff --git a/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.Designer.cs b/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.Designer.cs
new file mode 100644
index 0000000..005038a
--- /dev/null
+++ b/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.Designer.cs
@@ -0,0 +1,361 @@
+// <auto-generated />
+using System;
+using System.Net.NetworkInformation;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using PhoneToolMX.Data;
+
+#nullable disable
+
+namespace PhoneToolMX.Models.Migrations
+{
+    [DbContext(typeof(PTMXContext))]
+    [Migration("20231020205952_PrimaryExtension")]
+    partial class PrimaryExtension
+    {
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "6.0.23")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ExtensionPhone", b =>
+                {
+                    b.Property<int>("ExtensionsId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PhonesId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("ExtensionsId", "PhonesId");
+
+                    b.HasIndex("PhonesId");
+
+                    b.ToTable("ExtensionPhone");
+                });
+
+            modelBuilder.Entity("ExtensionUser", b =>
+                {
+                    b.Property<int>("ExtensionsId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("OwnersId")
+                        .HasColumnType("text");
+
+                    b.HasKey("ExtensionsId", "OwnersId");
+
+                    b.HasIndex("OwnersId");
+
+                    b.ToTable("ExtensionUser");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.CustomData", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<byte[]>("Data")
+                        .HasColumnType("bytea");
+
+                    b.Property<int>("DataType")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("FriendlyName")
+                        .HasMaxLength(16)
+                        .HasColumnType("character varying(16)");
+
+                    b.Property<int?>("PhoneId")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("Size")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PhoneId");
+
+                    b.ToTable("CustomData");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Extension", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<string>("DirectoryName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("ExtId")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("integer")
+                        .HasComputedColumnSql("\"Id\" + 1000", true);
+
+                    b.Property<int?>("HoldMusicId")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("Listed")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Password")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasDefaultValueSql("encode(gen_random_bytes(18), 'base64')");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("HoldMusicId");
+
+                    b.ToTable("Extensions");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<int?>("BackgroundId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("FriendlyName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<PhysicalAddress>("MacAddress")
+                        .IsRequired()
+                        .HasColumnType("macaddr");
+
+                    b.Property<int>("ModelId")
+                        .HasColumnType("integer");
+
+                    b.Property<int?>("PrimaryExtension")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BackgroundId");
+
+                    b.HasIndex("ModelId");
+
+                    b.ToTable("Phones");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.PhoneModel", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<long>("MaxExtensions")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("ModelName")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("PreVvxPolycom")
+                        .HasColumnType("boolean");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("PhoneModels");
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 0,
+                            MaxExtensions = 6L,
+                            ModelName = "Polycom VVX300/310",
+                            PreVvxPolycom = false
+                        });
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Role", b =>
+                {
+                    b.Property<string>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("text");
+
+                    b.Property<string>("NormalizedName")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Role");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.User", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text");
+
+                    b.Property<int>("AccessFailedCount")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Email")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("EmailConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("LockoutEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTimeOffset?>("LockoutEnd")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("NormalizedEmail")
+                        .HasColumnType("text");
+
+                    b.Property<string>("NormalizedUserName")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PasswordHash")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PhoneNumber")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("PhoneNumberConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("SecurityStamp")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("TwoFactorEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("UserName")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("PhoneUser", b =>
+                {
+                    b.Property<string>("OwnersId")
+                        .HasColumnType("text");
+
+                    b.Property<int>("PhonesId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("OwnersId", "PhonesId");
+
+                    b.HasIndex("PhonesId");
+
+                    b.ToTable("PhoneUser");
+                });
+
+            modelBuilder.Entity("ExtensionPhone", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Extension", null)
+                        .WithMany()
+                        .HasForeignKey("ExtensionsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany()
+                        .HasForeignKey("PhonesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("ExtensionUser", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Extension", null)
+                        .WithMany()
+                        .HasForeignKey("ExtensionsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("OwnersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.CustomData", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany("Ringtones")
+                        .HasForeignKey("PhoneId");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Extension", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.CustomData", "HoldMusic")
+                        .WithMany()
+                        .HasForeignKey("HoldMusicId");
+
+                    b.Navigation("HoldMusic");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.CustomData", "Background")
+                        .WithMany()
+                        .HasForeignKey("BackgroundId");
+
+                    b.HasOne("PhoneToolMX.Models.PhoneModel", "Model")
+                        .WithMany()
+                        .HasForeignKey("ModelId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Background");
+
+                    b.Navigation("Model");
+                });
+
+            modelBuilder.Entity("PhoneUser", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("OwnersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany()
+                        .HasForeignKey("PhonesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.Navigation("Ringtones");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.cs b/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.cs
new file mode 100644
index 0000000..cb677d5
--- /dev/null
+++ b/PhoneToolMX.Models/Migrations/20231020205952_PrimaryExtension.cs
@@ -0,0 +1,25 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PhoneToolMX.Models.Migrations
+{
+    public partial class PrimaryExtension : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "PrimaryExtension",
+                table: "Phones",
+                type: "integer",
+                nullable: true);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "PrimaryExtension",
+                table: "Phones");
+        }
+    }
+}
diff --git a/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.Designer.cs b/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.Designer.cs
new file mode 100644
index 0000000..492ce36
--- /dev/null
+++ b/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.Designer.cs
@@ -0,0 +1,369 @@
+// <auto-generated />
+using System;
+using System.Net.NetworkInformation;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using PhoneToolMX.Data;
+
+#nullable disable
+
+namespace PhoneToolMX.Models.Migrations
+{
+    [DbContext(typeof(PTMXContext))]
+    [Migration("20231020213049_PrimaryExtensionAsExtension")]
+    partial class PrimaryExtensionAsExtension
+    {
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "6.0.23")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ExtensionPhone", b =>
+                {
+                    b.Property<int>("ExtensionsId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PhonesId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("ExtensionsId", "PhonesId");
+
+                    b.HasIndex("PhonesId");
+
+                    b.ToTable("ExtensionPhone");
+                });
+
+            modelBuilder.Entity("ExtensionUser", b =>
+                {
+                    b.Property<int>("ExtensionsId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("OwnersId")
+                        .HasColumnType("text");
+
+                    b.HasKey("ExtensionsId", "OwnersId");
+
+                    b.HasIndex("OwnersId");
+
+                    b.ToTable("ExtensionUser");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.CustomData", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<byte[]>("Data")
+                        .HasColumnType("bytea");
+
+                    b.Property<int>("DataType")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("FriendlyName")
+                        .HasMaxLength(16)
+                        .HasColumnType("character varying(16)");
+
+                    b.Property<int?>("PhoneId")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("Size")
+                        .HasColumnType("bigint");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("PhoneId");
+
+                    b.ToTable("CustomData");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Extension", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<string>("DirectoryName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("ExtId")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("integer")
+                        .HasComputedColumnSql("\"Id\" + 1000", true);
+
+                    b.Property<int?>("HoldMusicId")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("Listed")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Password")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasDefaultValueSql("encode(gen_random_bytes(18), 'base64')");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("HoldMusicId");
+
+                    b.ToTable("Extensions");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<int?>("BackgroundId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("FriendlyName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<PhysicalAddress>("MacAddress")
+                        .IsRequired()
+                        .HasColumnType("macaddr");
+
+                    b.Property<int>("ModelId")
+                        .HasColumnType("integer");
+
+                    b.Property<int?>("PrimaryExtensionId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BackgroundId");
+
+                    b.HasIndex("ModelId");
+
+                    b.HasIndex("PrimaryExtensionId");
+
+                    b.ToTable("Phones");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.PhoneModel", b =>
+                {
+                    b.Property<int?>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int?>("Id"));
+
+                    b.Property<long>("MaxExtensions")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("ModelName")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("PreVvxPolycom")
+                        .HasColumnType("boolean");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("PhoneModels");
+
+                    b.HasData(
+                        new
+                        {
+                            Id = 0,
+                            MaxExtensions = 6L,
+                            ModelName = "Polycom VVX300/310",
+                            PreVvxPolycom = false
+                        });
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Role", b =>
+                {
+                    b.Property<string>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("text");
+
+                    b.Property<string>("NormalizedName")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Role");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.User", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text");
+
+                    b.Property<int>("AccessFailedCount")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ConcurrencyStamp")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Email")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("EmailConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("LockoutEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTimeOffset?>("LockoutEnd")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("NormalizedEmail")
+                        .HasColumnType("text");
+
+                    b.Property<string>("NormalizedUserName")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PasswordHash")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PhoneNumber")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("PhoneNumberConfirmed")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("SecurityStamp")
+                        .HasColumnType("text");
+
+                    b.Property<bool>("TwoFactorEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("UserName")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("PhoneUser", b =>
+                {
+                    b.Property<string>("OwnersId")
+                        .HasColumnType("text");
+
+                    b.Property<int>("PhonesId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("OwnersId", "PhonesId");
+
+                    b.HasIndex("PhonesId");
+
+                    b.ToTable("PhoneUser");
+                });
+
+            modelBuilder.Entity("ExtensionPhone", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Extension", null)
+                        .WithMany()
+                        .HasForeignKey("ExtensionsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany()
+                        .HasForeignKey("PhonesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("ExtensionUser", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Extension", null)
+                        .WithMany()
+                        .HasForeignKey("ExtensionsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("OwnersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.CustomData", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany("Ringtones")
+                        .HasForeignKey("PhoneId");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Extension", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.CustomData", "HoldMusic")
+                        .WithMany()
+                        .HasForeignKey("HoldMusicId");
+
+                    b.Navigation("HoldMusic");
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.CustomData", "Background")
+                        .WithMany()
+                        .HasForeignKey("BackgroundId");
+
+                    b.HasOne("PhoneToolMX.Models.PhoneModel", "Model")
+                        .WithMany()
+                        .HasForeignKey("ModelId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.Extension", "PrimaryExtension")
+                        .WithMany()
+                        .HasForeignKey("PrimaryExtensionId");
+
+                    b.Navigation("Background");
+
+                    b.Navigation("Model");
+
+                    b.Navigation("PrimaryExtension");
+                });
+
+            modelBuilder.Entity("PhoneUser", b =>
+                {
+                    b.HasOne("PhoneToolMX.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("OwnersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("PhoneToolMX.Models.Phone", null)
+                        .WithMany()
+                        .HasForeignKey("PhonesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("PhoneToolMX.Models.Phone", b =>
+                {
+                    b.Navigation("Ringtones");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.cs b/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.cs
new file mode 100644
index 0000000..81d4d29
--- /dev/null
+++ b/PhoneToolMX.Models/Migrations/20231020213049_PrimaryExtensionAsExtension.cs
@@ -0,0 +1,45 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PhoneToolMX.Models.Migrations
+{
+    public partial class PrimaryExtensionAsExtension : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.RenameColumn(
+                name: "PrimaryExtension",
+                table: "Phones",
+                newName: "PrimaryExtensionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Phones_PrimaryExtensionId",
+                table: "Phones",
+                column: "PrimaryExtensionId");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Phones_Extensions_PrimaryExtensionId",
+                table: "Phones",
+                column: "PrimaryExtensionId",
+                principalTable: "Extensions",
+                principalColumn: "Id");
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Phones_Extensions_PrimaryExtensionId",
+                table: "Phones");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Phones_PrimaryExtensionId",
+                table: "Phones");
+
+            migrationBuilder.RenameColumn(
+                name: "PrimaryExtensionId",
+                table: "Phones",
+                newName: "PrimaryExtension");
+        }
+    }
+}
diff --git a/PhoneToolMX.Models/Migrations/PTMXContextModelSnapshot.cs b/PhoneToolMX.Models/Migrations/PTMXContextModelSnapshot.cs
index 47245c4..dceadaa 100644
--- a/PhoneToolMX.Models/Migrations/PTMXContextModelSnapshot.cs
+++ b/PhoneToolMX.Models/Migrations/PTMXContextModelSnapshot.cs
@@ -141,12 +141,17 @@ namespace PhoneToolMX.Models.Migrations
                     b.Property<int>("ModelId")
                         .HasColumnType("integer");
 
+                    b.Property<int?>("PrimaryExtensionId")
+                        .HasColumnType("integer");
+
                     b.HasKey("Id");
 
                     b.HasIndex("BackgroundId");
 
                     b.HasIndex("ModelId");
 
+                    b.HasIndex("PrimaryExtensionId");
+
                     b.ToTable("Phones");
                 });
 
@@ -326,9 +331,15 @@ namespace PhoneToolMX.Models.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
+                    b.HasOne("PhoneToolMX.Models.Extension", "PrimaryExtension")
+                        .WithMany()
+                        .HasForeignKey("PrimaryExtensionId");
+
                     b.Navigation("Background");
 
                     b.Navigation("Model");
+
+                    b.Navigation("PrimaryExtension");
                 });
 
             modelBuilder.Entity("PhoneUser", b =>
diff --git a/PhoneToolMX.Models/Models/IModel.cs b/PhoneToolMX.Models/Models/IModel.cs
index 49335f8..a17077c 100644
--- a/PhoneToolMX.Models/Models/IModel.cs
+++ b/PhoneToolMX.Models/Models/IModel.cs
@@ -12,6 +12,8 @@ namespace PhoneToolMX.Models
             foreach (var prop in GetType().GetProperties().Where(p => p.CanWrite)) {
                 if (prop.GetValue(obj, null) is {} propVal) {
                     prop.SetValue(this, propVal, null);
+                } else if (prop.GetCustomAttributes(typeof(AllowNullAttribute)).FirstOrDefault() != null) {
+                    prop.SetValue(this, null, null);
                 }
             }
         }
diff --git a/PhoneToolMX.Models/Models/Phone.cs b/PhoneToolMX.Models/Models/Phone.cs
index c396439..8e34c2c 100644
--- a/PhoneToolMX.Models/Models/Phone.cs
+++ b/PhoneToolMX.Models/Models/Phone.cs
@@ -21,7 +21,10 @@ namespace PhoneToolMX.Models {
         
         [AlwaysInclude]
         public ICollection<Extension> Extensions { get; set; }
+        
         public CustomData Background { get; set; }
         public ICollection<CustomData> Ringtones { get; set; }
+        
+        public Extension PrimaryExtension { get; set; }
     }
 }
\ No newline at end of file
diff --git a/PhoneToolMX.Models/ViewModels/PhoneVM.cs b/PhoneToolMX.Models/ViewModels/PhoneVM.cs
index 68db836..67df3b9 100644
--- a/PhoneToolMX.Models/ViewModels/PhoneVM.cs
+++ b/PhoneToolMX.Models/ViewModels/PhoneVM.cs
@@ -1,6 +1,4 @@
 using PhoneToolMX.Data;
-using PhoneToolMX.Models;
-using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;
 using System.Net.NetworkInformation;
 
@@ -25,18 +23,25 @@ namespace PhoneToolMX.Models.ViewModels
         
         public ICollection<int?> Extensions { get; set; }
         
+        [AllowNull]
+        public int? PrimaryExtension { get; set; }
+        
         public int MaxExtensions { get; set; }
         
         public IOwnedModel ToEntity(PTMXContext ctx)
         {
+            var exts = Extensions?.Select(x => ctx.Extensions.FirstOrDefault(e => e.Id == x)).ToList();
             return new Phone
             {
                 Id = Id,
                 MacAddress = PhysicalAddress.Parse(MacAddress),
                 FriendlyName = FriendlyName,
                 Model = ctx.PhoneModels.FirstOrDefault(p => p.Id == Model)!,
-                Extensions = Extensions?.Select(x => ctx.Extensions.FirstOrDefault(e => e.Id == x)).ToList(),
+                Extensions = exts,
                 Owners = new List<User>(),
+                PrimaryExtension = PrimaryExtension != null
+                    ? exts?.FirstOrDefault(x => x.Id == PrimaryExtension)
+                    : null,
             };
         }
         
@@ -58,6 +63,7 @@ namespace PhoneToolMX.Models.ViewModels
                 Model = phoneEnt.Model!.Id,
                 Extensions = phoneEnt.Extensions?.Select(x => x.Id).ToList(),
                 MaxExtensions = (int)phoneEnt.Model!.MaxExtensions,
+                PrimaryExtension = phoneEnt.PrimaryExtension?.Id,
             };
         }
     }
diff --git a/PhoneToolMX/Controllers/PhoneController.cs b/PhoneToolMX/Controllers/PhoneController.cs
index 70b0fd0..19586fa 100644
--- a/PhoneToolMX/Controllers/PhoneController.cs
+++ b/PhoneToolMX/Controllers/PhoneController.cs
@@ -17,8 +17,10 @@ namespace PhoneToolMX.Controllers
         {
             var myExts = _context.GetOwned<Extension>(await CurrentUser());
             var phoneModels = _context.PhoneModels.ToList();
+            var selectedExts = pvm?.Extensions == null ? null : myExts.Where(x => pvm.Extensions.Contains(x.Id)).ToList();
             ViewBag.MyExtensions = myExts;
-            ViewBag.SelectedExtensions = pvm?.Extensions == null ? null : myExts.Where(x => pvm.Extensions.Contains(x.Id)).ToList();
+            ViewBag.SelectedExtensions = selectedExts;
+            ViewBag.PrimaryExtension = selectedExts?.FirstOrDefault(x => x.Id == (pvm.PrimaryExtension ?? -1));
             ViewBag.ModelNumbers = phoneModels;
             ViewBag.CurrentModel = pvm?.Model == null ? null : phoneModels.Where(m => m.Id == pvm.Model);
         }
diff --git a/PhoneToolMX/Views/Phone/_Form.cshtml b/PhoneToolMX/Views/Phone/_Form.cshtml
index aa5e92c..bbc0858 100644
--- a/PhoneToolMX/Views/Phone/_Form.cshtml
+++ b/PhoneToolMX/Views/Phone/_Form.cshtml
@@ -24,6 +24,14 @@
         <th>@Html.LabelFor(m => m.Extensions, "Extensions:")</th>
         <td>@Html.ListBoxFor(m => m.Extensions, new MultiSelectList(ViewBag.MyExtensions, "Id", "ListViewName", ViewBag.SelectedExtensions))
     </tr>
+    <tr>
+        <th>@Html.LabelFor(m => m.PrimaryExtension, "Primary Extension:")</th>
+        <td>@if (ViewBag.SelectedExtensions == null || ((ICollection<Extension>)ViewBag.SelectedExtensions).Count == 0) {
+            @Html.DropDownListFor(m => m.PrimaryExtension, new List<SelectListItem>(), "-- No Extensions Selected --", new { @disabled=true })
+        } else {
+            @Html.DropDownListFor(m => m.PrimaryExtension, new SelectList(ViewBag.SelectedExtensions, "Id", "ListViewName", ViewBag.PrimaryExtension), "None")
+        }</td>
+    </tr>
     <tr>
         <td colspan="2" align="right">
             <input type="reset" value="Reset" />
diff --git a/PolyProv/Controllers/ConfigController.cs b/PolyProv/Controllers/ConfigController.cs
index 60c2a16..977009c 100644
--- a/PolyProv/Controllers/ConfigController.cs
+++ b/PolyProv/Controllers/ConfigController.cs
@@ -54,6 +54,14 @@ namespace PolyProv.Controllers
         public IActionResult PhoneSettings(string addr)
         {
             var phone = GetByMacStr(addr);
+            
+            // ReSharper disable once InvertIf
+            if (phone?.PrimaryExtension is {} primary && phone.Extensions.FirstOrDefault() != primary) {
+                // primary extension exists and is not first, reorder so it's first
+                phone.Extensions.Remove(primary);
+                phone.Extensions = phone.Extensions.Prepend(primary).ToList();
+            }
+            
             return phone != null ? View("Phone", phone) : NotFound();
         }