diff --git a/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.Designer.cs b/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.Designer.cs
new file mode 100644
index 00000000..3cc9708b
--- /dev/null
+++ b/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.Designer.cs
@@ -0,0 +1,301 @@
+// <auto-generated />
+using System;
+using Geopilot.Api;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NetTopologySuite.Geometries;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace Geopilot.Api.Migrations
+{
+    [DbContext(typeof(Context))]
+    [Migration("20250107090507_EnableOptionalDeliveryAttributes")]
+    partial class EnableOptionalDeliveryAttributes
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.8")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "postgis");
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("Geopilot.Api.Models.Asset", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("AssetType")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<bool>("Deleted")
+                        .HasColumnType("boolean");
+
+                    b.Property<int?>("DeliveryId")
+                        .HasColumnType("integer");
+
+                    b.Property<byte[]>("FileHash")
+                        .IsRequired()
+                        .HasColumnType("bytea");
+
+                    b.Property<string>("OriginalFilename")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("SanitizedFilename")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DeliveryId");
+
+                    b.ToTable("Assets");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Delivery", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Comment")
+                        .HasColumnType("text");
+
+                    b.Property<DateTime>("Date")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("DeclaringUserId")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("Deleted")
+                        .HasColumnType("boolean");
+
+                    b.Property<Guid>("JobId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int?>("MandateId")
+                        .HasColumnType("integer");
+
+                    b.Property<bool?>("Partial")
+                        .HasColumnType("boolean");
+
+                    b.Property<int?>("PrecursorDeliveryId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DeclaringUserId");
+
+                    b.HasIndex("MandateId");
+
+                    b.HasIndex("PrecursorDeliveryId");
+
+                    b.ToTable("Deliveries");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Mandate", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("EvaluateComment")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<string>("EvaluatePartial")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<string>("EvaluatePrecursorDelivery")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<string[]>("FileTypes")
+                        .IsRequired()
+                        .HasColumnType("text[]");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Geometry>("SpatialExtent")
+                        .IsRequired()
+                        .HasColumnType("geometry");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Mandates");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Organisation", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Organisations");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.User", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("AuthIdentifier")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("FullName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<bool>("IsAdmin")
+                        .HasColumnType("boolean");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("MandateOrganisation", b =>
+                {
+                    b.Property<int>("MandatesId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("OrganisationsId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("MandatesId", "OrganisationsId");
+
+                    b.HasIndex("OrganisationsId");
+
+                    b.ToTable("MandateOrganisation");
+                });
+
+            modelBuilder.Entity("OrganisationUser", b =>
+                {
+                    b.Property<int>("OrganisationsId")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("UsersId")
+                        .HasColumnType("integer");
+
+                    b.HasKey("OrganisationsId", "UsersId");
+
+                    b.HasIndex("UsersId");
+
+                    b.ToTable("OrganisationUser");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Asset", b =>
+                {
+                    b.HasOne("Geopilot.Api.Models.Delivery", "Delivery")
+                        .WithMany("Assets")
+                        .HasForeignKey("DeliveryId");
+
+                    b.Navigation("Delivery");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Delivery", b =>
+                {
+                    b.HasOne("Geopilot.Api.Models.User", "DeclaringUser")
+                        .WithMany("Deliveries")
+                        .HasForeignKey("DeclaringUserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Geopilot.Api.Models.Mandate", "Mandate")
+                        .WithMany("Deliveries")
+                        .HasForeignKey("MandateId");
+
+                    b.HasOne("Geopilot.Api.Models.Delivery", "PrecursorDelivery")
+                        .WithMany()
+                        .HasForeignKey("PrecursorDeliveryId");
+
+                    b.Navigation("DeclaringUser");
+
+                    b.Navigation("Mandate");
+
+                    b.Navigation("PrecursorDelivery");
+                });
+
+            modelBuilder.Entity("MandateOrganisation", b =>
+                {
+                    b.HasOne("Geopilot.Api.Models.Mandate", null)
+                        .WithMany()
+                        .HasForeignKey("MandatesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Geopilot.Api.Models.Organisation", null)
+                        .WithMany()
+                        .HasForeignKey("OrganisationsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("OrganisationUser", b =>
+                {
+                    b.HasOne("Geopilot.Api.Models.Organisation", null)
+                        .WithMany()
+                        .HasForeignKey("OrganisationsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Geopilot.Api.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("UsersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Delivery", b =>
+                {
+                    b.Navigation("Assets");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.Mandate", b =>
+                {
+                    b.Navigation("Deliveries");
+                });
+
+            modelBuilder.Entity("Geopilot.Api.Models.User", b =>
+                {
+                    b.Navigation("Deliveries");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.cs b/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.cs
new file mode 100644
index 00000000..99d83b51
--- /dev/null
+++ b/src/Geopilot.Api/Migrations/20250107090507_EnableOptionalDeliveryAttributes.cs
@@ -0,0 +1,169 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Geopilot.Api.Migrations
+{
+    /// <inheritdoc />
+    public partial class EnableOptionalDeliveryAttributes : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Assets_Deliveries_DeliveryId",
+                table: "Assets");
+
+            migrationBuilder.DropForeignKey(
+                name: "FK_Deliveries_Mandates_MandateId",
+                table: "Deliveries");
+
+            migrationBuilder.AddColumn<string>(
+                name: "EvaluateComment",
+                table: "Mandates",
+                type: "varchar(24)",
+                nullable: false,
+                defaultValue: "");
+
+            migrationBuilder.AddColumn<string>(
+                name: "EvaluatePartial",
+                table: "Mandates",
+                type: "varchar(24)",
+                nullable: false,
+                defaultValue: "");
+
+            migrationBuilder.AddColumn<string>(
+                name: "EvaluatePrecursorDelivery",
+                table: "Mandates",
+                type: "varchar(24)",
+                nullable: false,
+                defaultValue: "");
+
+            migrationBuilder.AlterColumn<bool>(
+                name: "Partial",
+                table: "Deliveries",
+                type: "boolean",
+                nullable: true,
+                oldClrType: typeof(bool),
+                oldType: "boolean");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "MandateId",
+                table: "Deliveries",
+                type: "integer",
+                nullable: true,
+                oldClrType: typeof(int),
+                oldType: "integer");
+
+            migrationBuilder.AlterColumn<string>(
+                name: "Comment",
+                table: "Deliveries",
+                type: "text",
+                nullable: true,
+                oldClrType: typeof(string),
+                oldType: "text");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "DeliveryId",
+                table: "Assets",
+                type: "integer",
+                nullable: true,
+                oldClrType: typeof(int),
+                oldType: "integer");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Assets_Deliveries_DeliveryId",
+                table: "Assets",
+                column: "DeliveryId",
+                principalTable: "Deliveries",
+                principalColumn: "Id");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Deliveries_Mandates_MandateId",
+                table: "Deliveries",
+                column: "MandateId",
+                principalTable: "Mandates",
+                principalColumn: "Id");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Assets_Deliveries_DeliveryId",
+                table: "Assets");
+
+            migrationBuilder.DropForeignKey(
+                name: "FK_Deliveries_Mandates_MandateId",
+                table: "Deliveries");
+
+            migrationBuilder.DropColumn(
+                name: "EvaluateComment",
+                table: "Mandates");
+
+            migrationBuilder.DropColumn(
+                name: "EvaluatePartial",
+                table: "Mandates");
+
+            migrationBuilder.DropColumn(
+                name: "EvaluatePrecursorDelivery",
+                table: "Mandates");
+
+            migrationBuilder.AlterColumn<bool>(
+                name: "Partial",
+                table: "Deliveries",
+                type: "boolean",
+                nullable: false,
+                defaultValue: false,
+                oldClrType: typeof(bool),
+                oldType: "boolean",
+                oldNullable: true);
+
+            migrationBuilder.AlterColumn<int>(
+                name: "MandateId",
+                table: "Deliveries",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0,
+                oldClrType: typeof(int),
+                oldType: "integer",
+                oldNullable: true);
+
+            migrationBuilder.AlterColumn<string>(
+                name: "Comment",
+                table: "Deliveries",
+                type: "text",
+                nullable: false,
+                defaultValue: "",
+                oldClrType: typeof(string),
+                oldType: "text",
+                oldNullable: true);
+
+            migrationBuilder.AlterColumn<int>(
+                name: "DeliveryId",
+                table: "Assets",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0,
+                oldClrType: typeof(int),
+                oldType: "integer",
+                oldNullable: true);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Assets_Deliveries_DeliveryId",
+                table: "Assets",
+                column: "DeliveryId",
+                principalTable: "Deliveries",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.Cascade);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Deliveries_Mandates_MandateId",
+                table: "Deliveries",
+                column: "MandateId",
+                principalTable: "Mandates",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.Cascade);
+        }
+    }
+}
diff --git a/src/Geopilot.Api/Migrations/ContextModelSnapshot.cs b/src/Geopilot.Api/Migrations/ContextModelSnapshot.cs
index b72df553..2d647220 100644
--- a/src/Geopilot.Api/Migrations/ContextModelSnapshot.cs
+++ b/src/Geopilot.Api/Migrations/ContextModelSnapshot.cs
@@ -18,7 +18,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
         {
 #pragma warning disable 612, 618
             modelBuilder
-                .HasAnnotation("ProductVersion", "7.0.11")
+                .HasAnnotation("ProductVersion", "8.0.8")
                 .HasAnnotation("Relational:MaxIdentifierLength", 63);
 
             NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "postgis");
@@ -39,7 +39,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.Property<bool>("Deleted")
                         .HasColumnType("boolean");
 
-                    b.Property<int>("DeliveryId")
+                    b.Property<int?>("DeliveryId")
                         .HasColumnType("integer");
 
                     b.Property<byte[]>("FileHash")
@@ -70,7 +70,6 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
 
                     b.Property<string>("Comment")
-                        .IsRequired()
                         .HasColumnType("text");
 
                     b.Property<DateTime>("Date")
@@ -85,10 +84,10 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.Property<Guid>("JobId")
                         .HasColumnType("uuid");
 
-                    b.Property<int>("MandateId")
+                    b.Property<int?>("MandateId")
                         .HasColumnType("integer");
 
-                    b.Property<bool>("Partial")
+                    b.Property<bool?>("Partial")
                         .HasColumnType("boolean");
 
                     b.Property<int?>("PrecursorDeliveryId")
@@ -113,6 +112,18 @@ protected override void BuildModel(ModelBuilder modelBuilder)
 
                     NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("Id"));
 
+                    b.Property<string>("EvaluateComment")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<string>("EvaluatePartial")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
+                    b.Property<string>("EvaluatePrecursorDelivery")
+                        .IsRequired()
+                        .HasColumnType("varchar(24)");
+
                     b.Property<string[]>("FileTypes")
                         .IsRequired()
                         .HasColumnType("text[]");
@@ -209,9 +220,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                 {
                     b.HasOne("Geopilot.Api.Models.Delivery", "Delivery")
                         .WithMany("Assets")
-                        .HasForeignKey("DeliveryId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
+                        .HasForeignKey("DeliveryId");
 
                     b.Navigation("Delivery");
                 });
@@ -226,9 +235,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
 
                     b.HasOne("Geopilot.Api.Models.Mandate", "Mandate")
                         .WithMany("Deliveries")
-                        .HasForeignKey("MandateId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
+                        .HasForeignKey("MandateId");
 
                     b.HasOne("Geopilot.Api.Models.Delivery", "PrecursorDelivery")
                         .WithMany()
diff --git a/src/Geopilot.Api/Models/Delivery.cs b/src/Geopilot.Api/Models/Delivery.cs
index f53fb189..35629fe0 100644
--- a/src/Geopilot.Api/Models/Delivery.cs
+++ b/src/Geopilot.Api/Models/Delivery.cs
@@ -38,7 +38,7 @@ public class Delivery
     /// <summary>
     /// Indicate whether the delivery contains partial data.
     /// </summary>
-    public bool Partial { get; set; }
+    public bool? Partial { get; set; }
 
     /// <summary>
     /// The previous delivery on the same <see cref="Mandate"/>.
@@ -48,7 +48,7 @@ public class Delivery
     /// <summary>
     /// Comment to describe the delivery.
     /// </summary>
-    public string Comment { get; set; } = string.Empty;
+    public string? Comment { get; set; } = string.Empty;
 
     /// <summary>
     /// The deletion status of the delivery.
diff --git a/src/Geopilot.Api/Models/FieldEvaluationType.cs b/src/Geopilot.Api/Models/FieldEvaluationType.cs
new file mode 100644
index 00000000..a2f17abf
--- /dev/null
+++ b/src/Geopilot.Api/Models/FieldEvaluationType.cs
@@ -0,0 +1,23 @@
+namespace Geopilot.Api.Models
+{
+    /// <summary>
+    /// Defines how <see cref="Delivery"/> fileds have to be evaluated.
+    /// </summary>
+    public enum FieldEvaluationType
+    {
+        /// <summary>
+        /// Field must not contain any value.
+        /// </summary>
+        NotEvaluated,
+
+        /// <summary>
+        /// Field may contain a value but must not.
+        /// </summary>
+        Optional,
+
+        /// <summary>
+        /// Field must contan a value.
+        /// </summary>
+        Required,
+    }
+}
diff --git a/src/Geopilot.Api/Models/Mandate.cs b/src/Geopilot.Api/Models/Mandate.cs
index 582dbfdf..7cb7e41b 100644
--- a/src/Geopilot.Api/Models/Mandate.cs
+++ b/src/Geopilot.Api/Models/Mandate.cs
@@ -1,4 +1,5 @@
-using NetTopologySuite.Geometries;
+using Microsoft.VisualBasic.FileIO;
+using NetTopologySuite.Geometries;
 using System.ComponentModel.DataAnnotations.Schema;
 using System.Text.Json.Serialization;
 
@@ -40,6 +41,24 @@ public class Mandate
     [NotMapped]
     public List<Coordinate> Coordinates { get; set; } = new List<Coordinate>();
 
+    /// <summary>
+    /// Defines how <see cref="Delivery.PrecursorDelivery"/> is evaluated.
+    /// </summary>
+    [Column(TypeName = "varchar(24)")]
+    public FieldEvaluationType EvaluatePrecursorDelivery { get; set; }
+
+    /// <summary>
+    /// Defines how <see cref="Delivery.Partial"/> is evaluated.
+    /// </summary>
+    [Column(TypeName = "varchar(24)")]
+    public FieldEvaluationType EvaluatePartial { get; set; }
+
+    /// <summary>
+    /// Defines how <see cref="Delivery.Comment"/> is evaluated.
+    /// </summary>
+    [Column(TypeName = "varchar(24)")]
+    public FieldEvaluationType EvaluateComment { get; set; }
+
     /// <summary>
     /// Organisations allowed to deliver data fulfilling the mandate.
     /// </summary>