diff --git a/src-ui/messages.xlf b/src-ui/messages.xlf
index c4e70f1fe..dc25ca462 100644
--- a/src-ui/messages.xlf
+++ b/src-ui/messages.xlf
@@ -544,7 +544,7 @@
         </context-group>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html</context>
-          <context context-type="linenumber">19</context>
+          <context context-type="linenumber">36</context>
         </context-group>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/document-type-edit-dialog/document-type-edit-dialog.component.html</context>
@@ -1447,6 +1447,10 @@
           <context context-type="sourcefile">src/app/components/admin/users-groups/users-groups.component.html</context>
           <context context-type="linenumber">76</context>
         </context-group>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html</context>
+          <context context-type="linenumber">26</context>
+        </context-group>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/mail-rule-edit-dialog/mail-rule-edit-dialog.component.ts</context>
           <context context-type="linenumber">53</context>
@@ -1624,7 +1628,7 @@
         </context-group>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html</context>
-          <context context-type="linenumber">18</context>
+          <context context-type="linenumber">35</context>
         </context-group>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/document-type-edit-dialog/document-type-edit-dialog.component.html</context>
@@ -3445,18 +3449,25 @@
           <context context-type="linenumber">14</context>
         </context-group>
       </trans-unit>
+      <trans-unit id="4910631867841099191" datatype="html">
+        <source>Add option</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html</context>
+          <context context-type="linenumber">20</context>
+        </context-group>
+      </trans-unit>
       <trans-unit id="528950215505228201" datatype="html">
         <source>Create new custom field</source>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts</context>
-          <context context-type="linenumber">36</context>
+          <context context-type="linenumber">44</context>
         </context-group>
       </trans-unit>
       <trans-unit id="8751213029607178010" datatype="html">
         <source>Edit custom field</source>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts</context>
-          <context context-type="linenumber">40</context>
+          <context context-type="linenumber">48</context>
         </context-group>
       </trans-unit>
       <trans-unit id="6672809941092516947" datatype="html">
diff --git a/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.spec.ts b/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.spec.ts
index 43d101611..8706cfac1 100644
--- a/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.spec.ts
+++ b/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.spec.ts
@@ -16,7 +16,9 @@ const customFields: CustomField[] = [
     id: 4,
     name: 'Field 4',
     data_type: CustomFieldDataType.Select,
-    extra_data: ['Option 1', 'Option 2', 'Option 3'],
+    extra_data: {
+      select_options: ['Option 1', 'Option 2', 'Option 3'],
+    },
   },
 ]
 const document: Document = {
diff --git a/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.ts b/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.ts
index 1b309506b..7c97c660a 100644
--- a/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.ts
+++ b/src-ui/src/app/components/common/custom-field-display/custom-field-display.component.ts
@@ -115,8 +115,8 @@ export class CustomFieldDisplayComponent implements OnInit, OnDestroy {
     return this.docLinkDocuments?.find((d) => d.id === docId)?.title
   }
 
-  public getSelectValue(field: CustomField, value: number): string {
-    return field.extra_data[value]
+  public getSelectValue(field: CustomField, index: number): string {
+    return field.extra_data.select_options[index]
   }
 
   ngOnDestroy(): void {
diff --git a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html
index 681f4d8c7..2c8d5493d 100644
--- a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html
+++ b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.html
@@ -13,6 +13,23 @@
     @if (typeFieldDisabled) {
       <small class="d-block mt-n2" i18n>Data type cannot be changed after a field is created</small>
     }
+    <div [formGroup]="objectForm.controls.extra_data">
+      @switch (objectForm.get('data_type').value) {
+        @case (CustomFieldDataType.Select) {
+          <button type="button" class="btn btn-sm btn-primary mb-2" (click)="addSelectOption()">
+            <span i18n>Add option</span>&nbsp;<i class="bi bi-plus"></i>
+          </button>
+          <div formArrayName="select_options">
+            @for (option of objectForm.controls.extra_data.controls.select_options.controls; track option; let i = $index) {
+              <div class="input-group input-group-sm my-2">
+                <input type="text" class="form-control" [formControl]="option" autocomplete="off">
+                <button type="button" class="btn btn-outline-danger" (click)="removeSelectOption(i)" i18n>Delete</button>
+              </div>
+            }
+          </div>
+        }
+      }
+      </div>
   </div>
   <div class="modal-footer">
     <button type="button" class="btn btn-outline-secondary" (click)="cancel()" i18n [disabled]="networkActive">Cancel</button>
diff --git a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.spec.ts b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.spec.ts
index 98fe73dc8..03a93b3f5 100644
--- a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.spec.ts
+++ b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.spec.ts
@@ -63,4 +63,25 @@ describe('CustomFieldEditDialogComponent', () => {
     component.ngOnInit()
     expect(component.objectForm.get('data_type').disabled).toBeTruthy()
   })
+
+  it('should support add / remove select options', () => {
+    component.dialogMode = EditDialogMode.CREATE
+    fixture.detectChanges()
+    component.ngOnInit()
+    expect(
+      component.objectForm.get('extra_data').get('select_options').value.length
+    ).toBe(0)
+    component.addSelectOption()
+    expect(
+      component.objectForm.get('extra_data').get('select_options').value.length
+    ).toBe(1)
+    component.addSelectOption()
+    expect(
+      component.objectForm.get('extra_data').get('select_options').value.length
+    ).toBe(2)
+    component.removeSelectOption(0)
+    expect(
+      component.objectForm.get('extra_data').get('select_options').value.length
+    ).toBe(1)
+  })
 })
diff --git a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts
index 570b93ae5..e31c089b1 100644
--- a/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts
+++ b/src-ui/src/app/components/common/edit-dialog/custom-field-edit-dialog/custom-field-edit-dialog.component.ts
@@ -1,7 +1,11 @@
 import { Component, OnInit } from '@angular/core'
-import { FormGroup, FormControl } from '@angular/forms'
+import { FormGroup, FormControl, FormArray } from '@angular/forms'
 import { NgbActiveModal } from '@ng-bootstrap/ng-bootstrap'
-import { DATA_TYPE_LABELS, CustomField } from 'src/app/data/custom-field'
+import {
+  DATA_TYPE_LABELS,
+  CustomField,
+  CustomFieldDataType,
+} from 'src/app/data/custom-field'
 import { CustomFieldsService } from 'src/app/services/rest/custom-fields.service'
 import { UserService } from 'src/app/services/rest/user.service'
 import { SettingsService } from 'src/app/services/settings.service'
@@ -16,6 +20,13 @@ export class CustomFieldEditDialogComponent
   extends EditDialogComponent<CustomField>
   implements OnInit
 {
+  CustomFieldDataType = CustomFieldDataType
+
+  private get selectOptions(): FormArray {
+    return (this.objectForm.controls.extra_data as FormGroup).controls
+      .select_options as FormArray
+  }
+
   constructor(
     service: CustomFieldsService,
     activeModal: NgbActiveModal,
@@ -44,6 +55,9 @@ export class CustomFieldEditDialogComponent
     return new FormGroup({
       name: new FormControl(null),
       data_type: new FormControl(null),
+      extra_data: new FormGroup({
+        select_options: new FormArray([]),
+      }),
     })
   }
 
@@ -54,4 +68,12 @@ export class CustomFieldEditDialogComponent
   get typeFieldDisabled(): boolean {
     return this.dialogMode === EditDialogMode.EDIT
   }
+
+  public addSelectOption() {
+    this.selectOptions.push(new FormControl(''))
+  }
+
+  public removeSelectOption(index: number) {
+    this.selectOptions.removeAt(index)
+  }
 }
diff --git a/src-ui/src/app/components/document-detail/document-detail.component.html b/src-ui/src/app/components/document-detail/document-detail.component.html
index 370202f4b..d970d93b3 100644
--- a/src-ui/src/app/components/document-detail/document-detail.component.html
+++ b/src-ui/src/app/components/document-detail/document-detail.component.html
@@ -189,7 +189,7 @@
                     @case (CustomFieldDataType.Select) {
                       <pngx-input-select formControlName="value"
                       [title]="getCustomFieldFromInstance(fieldInstance)?.name"
-                      [itemsArray]="getCustomFieldFromInstance(fieldInstance)?.extra_data"
+                      [itemsArray]="getCustomFieldFromInstance(fieldInstance)?.extra_data.select_options"
                       [allowNull]="true"
                       [horizontal]="true"
                       [removable]="userIsOwner"
diff --git a/src-ui/src/app/data/custom-field.ts b/src-ui/src/app/data/custom-field.ts
index 54f6045bc..a60c5ac2a 100644
--- a/src-ui/src/app/data/custom-field.ts
+++ b/src-ui/src/app/data/custom-field.ts
@@ -55,5 +55,7 @@ export interface CustomField extends ObjectWithId {
   data_type: CustomFieldDataType
   name: string
   created?: Date
-  extra_data?: any
+  extra_data?: {
+    select_options?: string[]
+  }
 }
diff --git a/src/documents/serialisers.py b/src/documents/serialisers.py
index 4da4bf6d6..f4b36f884 100644
--- a/src/documents/serialisers.py
+++ b/src/documents/serialisers.py
@@ -480,10 +480,14 @@ class CustomFieldSerializer(serializers.ModelSerializer):
         if (
             "data_type" in attrs
             and attrs["data_type"] == CustomField.FieldDataType.SELECT
-            and ("extra_data" not in attrs or not isinstance(attrs["extra_data"], list))
+            and (
+                "extra_data" not in attrs
+                or "select_options" not in attrs["extra_data"]
+                or not isinstance(attrs["extra_data"]["select_options"], list)
+            )
         ):
             raise serializers.ValidationError(
-                {"error": "extra_data must be a list"},
+                {"error": "extra_data.select_options must be a list"},
             )
         return super().validate(attrs)
 
@@ -574,11 +578,12 @@ class CustomFieldInstanceSerializer(serializers.ModelSerializer):
             elif field.data_type == CustomField.FieldDataType.STRING:
                 MaxLengthValidator(limit_value=128)(data["value"])
             elif field.data_type == CustomField.FieldDataType.SELECT:
+                select_options = field.extra_data["select_options"]
                 try:
-                    field.extra_data[data["value"]]
+                    select_options[data["value"]]
                 except Exception:
                     raise serializers.ValidationError(
-                        f"Value must be index of an element in {field.extra_data}",
+                        f"Value must be index of an element in {select_options}",
                     )
 
         return data
diff --git a/src/documents/tests/test_api_custom_fields.py b/src/documents/tests/test_api_custom_fields.py
index df0631366..edebf7f3c 100644
--- a/src/documents/tests/test_api_custom_fields.py
+++ b/src/documents/tests/test_api_custom_fields.py
@@ -59,7 +59,9 @@ class TestCustomFieldsAPI(DirectoriesMixin, APITestCase):
                 {
                     "data_type": "select",
                     "name": "Select Field",
-                    "extra_data": ["Option 1", "Option 2"],
+                    "extra_data": {
+                        "select_options": ["Option 1", "Option 2"],
+                    },
                 },
             ),
             content_type="application/json",
@@ -68,7 +70,10 @@ class TestCustomFieldsAPI(DirectoriesMixin, APITestCase):
 
         data = resp.json()
 
-        self.assertCountEqual(data["extra_data"], ["Option 1", "Option 2"])
+        self.assertCountEqual(
+            data["extra_data"]["select_options"],
+            ["Option 1", "Option 2"],
+        )
 
     def test_create_custom_field_nonunique_name(self):
         """
@@ -93,6 +98,45 @@ class TestCustomFieldsAPI(DirectoriesMixin, APITestCase):
         )
         self.assertEqual(resp.status_code, status.HTTP_400_BAD_REQUEST)
 
+    def test_create_custom_field_select_invalid_options(self):
+        """
+        GIVEN:
+            - Custom field does not exist
+        WHEN:
+            - API request to create custom field with invalid select options
+        THEN:
+            - HTTP 400 is returned
+        """
+
+        # Not a list
+        resp = self.client.post(
+            self.ENDPOINT,
+            json.dumps(
+                {
+                    "data_type": "select",
+                    "name": "Select Field",
+                    "extra_data": {
+                        "select_options": "not a list",
+                    },
+                },
+            ),
+            content_type="application/json",
+        )
+        self.assertEqual(resp.status_code, status.HTTP_400_BAD_REQUEST)
+
+        # No options
+        resp = self.client.post(
+            self.ENDPOINT,
+            json.dumps(
+                {
+                    "data_type": "select",
+                    "name": "Select Field",
+                },
+            ),
+            content_type="application/json",
+        )
+        self.assertEqual(resp.status_code, status.HTTP_400_BAD_REQUEST)
+
     def test_create_custom_field_instance(self):
         """
         GIVEN:
@@ -155,7 +199,9 @@ class TestCustomFieldsAPI(DirectoriesMixin, APITestCase):
         custom_field_select = CustomField.objects.create(
             name="Test Custom Field Select",
             data_type=CustomField.FieldDataType.SELECT,
-            extra_data=["Option 1", "Option 2"],
+            extra_data={
+                "select_options": ["Option 1", "Option 2"],
+            },
         )
 
         date_value = date.today()
@@ -614,7 +660,9 @@ class TestCustomFieldsAPI(DirectoriesMixin, APITestCase):
         custom_field_select = CustomField.objects.create(
             name="Test Custom Field SELECT",
             data_type=CustomField.FieldDataType.SELECT,
-            extra_data=["Option 1", "Option 2"],
+            extra_data={
+                "select_options": ["Option 1", "Option 2"],
+            },
         )
 
         resp = self.client.patch(