diff --git a/source/frontend/src/features/mapSideBar/acquisition/add/models.test.ts b/source/frontend/src/features/mapSideBar/acquisition/add/models.test.ts
index 4782e47c17..33f2d6ab10 100644
--- a/source/frontend/src/features/mapSideBar/acquisition/add/models.test.ts
+++ b/source/frontend/src/features/mapSideBar/acquisition/add/models.test.ts
@@ -201,5 +201,43 @@ describe('Create acquisition model tests', () => {
         } as ApiGen_Concepts_AcquisitionFileTeam),
       );
     });
+
+    it('omits notice of claim when date and comment are empty strings', () => {
+      const model = new AcquisitionForm();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiAcquisitionFile = model.toApi();
+
+      expect(apiAcquisitionFile.noticeOfClaim).toEqual([]);
+    });
+
+    it('normalizes notice of claim values before sending to api', () => {
+      const model = new AcquisitionForm();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '  Test comment  ',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiAcquisitionFile = model.toApi();
+
+      expect(apiAcquisitionFile.noticeOfClaim).toHaveLength(1);
+      expect(apiAcquisitionFile.noticeOfClaim?.[0]).toEqual(
+        expect.objectContaining({
+          comment: 'Test comment',
+          receivedDate: null,
+        }),
+      );
+    });
   });
 });
diff --git a/source/frontend/src/features/mapSideBar/acquisition/add/models.ts b/source/frontend/src/features/mapSideBar/acquisition/add/models.ts
index 79de49e13d..578c87734b 100644
--- a/source/frontend/src/features/mapSideBar/acquisition/add/models.ts
+++ b/source/frontend/src/features/mapSideBar/acquisition/add/models.ts
@@ -14,7 +14,7 @@ import {
   stringToNumberOrNull,
   toTypeCodeNullable,
 } from '@/utils/formUtils';
-import { exists, isValidId, isValidIsoDateTime } from '@/utils/utils';
+import { exists, isValidId, isValidIsoDateTime, isValidString } from '@/utils/utils';
 
 import { PropertyForm } from '../../shared/models';
 import { ChecklistItemFormModel } from '../../shared/tabs/checklist/update/models';
@@ -81,6 +81,19 @@ export class AcquisitionForm implements WithAcquisitionTeam, WithAcquisitionOwne
   toApi(): ApiGen_Concepts_AcquisitionFile {
     const fileProperties = this.properties.map(x => this.toPropertyApi(x));
     const sortedProperties = applyDisplayOrder(fileProperties);
+    const noticeOfClaim: ApiGen_Concepts_NoticeOfClaim | null = this.noticeOfClaim
+      ? {
+          ...this.noticeOfClaim,
+          receivedDate: isValidString(this.noticeOfClaim?.receivedDate)
+            ? this.noticeOfClaim.receivedDate
+            : null,
+          comment: isValidString(this.noticeOfClaim?.comment?.trim())
+            ? this.noticeOfClaim.comment.trim()
+            : null,
+        }
+      : null;
+    const hasNoticeOfClaim =
+      isValidString(noticeOfClaim?.receivedDate) || isValidString(noticeOfClaim?.comment);
 
     return {
       id: this.id ?? 0,
@@ -136,7 +149,7 @@ export class AcquisitionForm implements WithAcquisitionTeam, WithAcquisitionOwne
       legacyStakeholders: null,
       product: null,
       project: null,
-      noticeOfClaim: exists(this.noticeOfClaim) ? [this.noticeOfClaim] : [],
+      noticeOfClaim: hasNoticeOfClaim && noticeOfClaim ? [noticeOfClaim] : [],
       ...getEmptyBaseAudit(this.rowVersion),
     };
   }
diff --git a/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/UpdateAcquisitionFileYupSchema.ts b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/UpdateAcquisitionFileYupSchema.ts
index 7ef81468ef..344a2aff86 100644
--- a/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/UpdateAcquisitionFileYupSchema.ts
+++ b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/UpdateAcquisitionFileYupSchema.ts
@@ -42,7 +42,10 @@ export const UpdateAcquisitionFileYupSchema = yup
       .nullable()
       .max(2000, 'Physical file details must be at most ${max} characters'),
     noticeOfClaim: yup.object().shape({
-      comment: yup.string().max(4000, 'Notice of claim comment must be at most ${max} characters'),
+      comment: yup
+        .string()
+        .nullable()
+        .max(4000, 'Notice of claim comment must be at most ${max} characters'),
     }),
   })
   .concat(UpdateAcquisitionTeamYupSchema)
diff --git a/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.test.ts b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.test.ts
new file mode 100644
index 0000000000..7ccaa99da7
--- /dev/null
+++ b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.test.ts
@@ -0,0 +1,43 @@
+import { UpdateAcquisitionSummaryFormModel } from './models';
+
+describe('UpdateAcquisitionSummaryFormModel', () => {
+  describe('toApi noticeOfClaim handling', () => {
+    it('omits noticeOfClaim when date and comment are empty', () => {
+      const model = new UpdateAcquisitionSummaryFormModel();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiModel = model.toApi();
+
+      expect(apiModel.noticeOfClaim).toEqual([]);
+    });
+
+    it('normalizes empty date to null and trims comment', () => {
+      const model = new UpdateAcquisitionSummaryFormModel();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '  file update comment  ',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiModel = model.toApi();
+
+      expect(apiModel.noticeOfClaim).toHaveLength(1);
+      expect(apiModel.noticeOfClaim?.[0]).toEqual(
+        expect.objectContaining({
+          comment: 'file update comment',
+          receivedDate: null,
+        }),
+      );
+    });
+  });
+});
diff --git a/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.ts b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.ts
index a5039bd80c..e80f43b15b 100644
--- a/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.ts
+++ b/source/frontend/src/features/mapSideBar/acquisition/tabs/fileDetails/update/models.ts
@@ -9,7 +9,7 @@ import { ApiGen_Concepts_InterestHolder } from '@/models/api/generated/ApiGen_Co
 import { ApiGen_Concepts_NoticeOfClaim } from '@/models/api/generated/ApiGen_Concepts_NoticeOfClaim';
 import { getEmptyBaseAudit } from '@/models/defaultInitializers';
 import { fromTypeCode, fromTypeCodeNullable, toTypeCodeNullable } from '@/utils/formUtils';
-import { exists, isValidId, isValidIsoDateTime } from '@/utils/utils';
+import { exists, isValidId, isValidIsoDateTime, isValidString } from '@/utils/utils';
 
 import {
   AcquisitionOwnerFormModel,
@@ -79,6 +79,20 @@ export class UpdateAcquisitionSummaryFormModel
   noticeOfClaim: ApiGen_Concepts_NoticeOfClaim;
 
   toApi(): ApiGen_Concepts_AcquisitionFile {
+    const noticeOfClaim: ApiGen_Concepts_NoticeOfClaim | null = this.noticeOfClaim
+      ? {
+          ...this.noticeOfClaim,
+          receivedDate: isValidString(this.noticeOfClaim?.receivedDate)
+            ? this.noticeOfClaim.receivedDate
+            : null,
+          comment: isValidString(this.noticeOfClaim?.comment?.trim())
+            ? this.noticeOfClaim.comment.trim()
+            : null,
+        }
+      : null;
+    const hasNoticeOfClaim =
+      isValidString(noticeOfClaim?.receivedDate) || isValidString(noticeOfClaim?.comment);
+
     return {
       id: this.id || 0,
       parentAcquisitionFileId: isValidId(this.parentAcquisitionFileId)
@@ -143,7 +157,7 @@ export class UpdateAcquisitionSummaryFormModel
       product: null,
       project: null,
       totalAllowableCompensation: null,
-      noticeOfClaim: exists(this.noticeOfClaim) ? [this.noticeOfClaim] : [],
+      noticeOfClaim: hasNoticeOfClaim && noticeOfClaim ? [noticeOfClaim] : [],
       ...getEmptyBaseAudit(this.rowVersion),
     };
   }
diff --git a/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.test.ts b/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.test.ts
new file mode 100644
index 0000000000..9428048fc8
--- /dev/null
+++ b/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.test.ts
@@ -0,0 +1,65 @@
+import { ManagementFormModel } from './ManagementFormModel';
+
+describe('ManagementFormModel', () => {
+  describe('toApi noticeOfClaim handling', () => {
+    it('omits noticeOfClaim when date and comment are empty', () => {
+      const model = new ManagementFormModel();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiModel = model.toApi();
+
+      expect(apiModel.noticeOfClaim).toEqual([]);
+    });
+
+    it('normalizes empty date to null and trims comment', () => {
+      const model = new ManagementFormModel();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '  comment from formik  ',
+        receivedDate: '',
+        rowVersion: null,
+      };
+
+      const apiModel = model.toApi();
+
+      expect(apiModel.noticeOfClaim).toHaveLength(1);
+      expect(apiModel.noticeOfClaim?.[0]).toEqual(
+        expect.objectContaining({
+          comment: 'comment from formik',
+          receivedDate: null,
+        }),
+      );
+    });
+
+    it('keeps receivedDate when provided and normalizes empty comment', () => {
+      const model = new ManagementFormModel();
+      model.noticeOfClaim = {
+        id: null,
+        acquisitionFileId: null,
+        managementFileId: null,
+        comment: '   ',
+        receivedDate: '2026-04-17',
+        rowVersion: null,
+      };
+
+      const apiModel = model.toApi();
+
+      expect(apiModel.noticeOfClaim).toHaveLength(1);
+      expect(apiModel.noticeOfClaim?.[0]).toEqual(
+        expect.objectContaining({
+          comment: null,
+          receivedDate: '2026-04-17',
+        }),
+      );
+    });
+  });
+});
diff --git a/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.ts b/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.ts
index 2bfc9e0c79..6bbe11348d 100644
--- a/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.ts
+++ b/source/frontend/src/features/mapSideBar/management/models/ManagementFormModel.ts
@@ -12,7 +12,7 @@ import { ApiGen_Concepts_NoticeOfClaim } from '@/models/api/generated/ApiGen_Con
 import { getEmptyBaseAudit } from '@/models/defaultInitializers';
 import { applyDisplayOrder } from '@/utils';
 import { fromTypeCode, toNullableId, toTypeCodeNullable } from '@/utils/formUtils';
-import { exists, isValidId } from '@/utils/utils';
+import { exists, isValidId, isValidString } from '@/utils/utils';
 
 import { PropertyForm } from '../../shared/models';
 import { ManagementTeamSubFormModel, WithManagementTeam } from './ManagementTeamSubFormModel';
@@ -50,6 +50,19 @@ export class ManagementFormModel implements WithManagementTeam {
     const sortedProperties = applyDisplayOrder(fileProperties);
     const personId = this.responsiblePayer?.personId ?? null;
     const organizationId = !personId ? this.responsiblePayer?.organizationId ?? null : null;
+    const noticeOfClaim: ApiGen_Concepts_NoticeOfClaim | null = this.noticeOfClaim
+      ? {
+          ...this.noticeOfClaim,
+          receivedDate: isValidString(this.noticeOfClaim?.receivedDate)
+            ? this.noticeOfClaim.receivedDate
+            : null,
+          comment: isValidString(this.noticeOfClaim?.comment?.trim())
+            ? this.noticeOfClaim.comment.trim()
+            : null,
+        }
+      : null;
+    const hasNoticeOfClaim =
+      isValidString(noticeOfClaim?.receivedDate) || isValidString(noticeOfClaim?.comment);
 
     return {
       id: this.id ?? 0,
@@ -81,7 +94,8 @@ export class ManagementFormModel implements WithManagementTeam {
         .filter(exists),
       fileProperties: sortedProperties ?? [],
       ...getEmptyBaseAudit(this.rowVersion),
-      noticeOfClaim: exists(this.noticeOfClaim) ? [this.noticeOfClaim] : [],
+      noticeOfClaim: hasNoticeOfClaim && noticeOfClaim ? [noticeOfClaim] : [],
+      ...getEmptyBaseAudit(this.rowVersion),
     };
   }