diff --git a/src/api/CommentResource.ts b/src/api/CommentResource.ts
new file mode 100644
index 000000000..807be3375
--- /dev/null
+++ b/src/api/CommentResource.ts
@@ -0,0 +1,35 @@
+import axios, { AxiosResponse } from 'axios';
+
+export interface CommentRequest {
+	donationId: number;
+	updateToken: string;
+	comment: string;
+	withName: boolean;
+	isPublic: boolean;
+}
+
+interface CommentResponse {
+	status: string;
+	message: string;
+}
+
+export interface CommentResource {
+	post: ( data: CommentRequest ) => Promise<string>;
+}
+
+export class ApiCommentResource implements CommentResource {
+	postEndpoint: string;
+
+	constructor( postEndpoint: string ) {
+		this.postEndpoint = postEndpoint;
+	}
+
+	post( data: CommentRequest ): Promise<string> {
+		return axios.post( this.postEndpoint, data ).then( ( validationResult: AxiosResponse<CommentResponse> ) => {
+			if ( validationResult.data.status !== 'OK' ) {
+				return Promise.reject( validationResult.data.message );
+			}
+			return validationResult.data.message;
+		} );
+	}
+}
diff --git a/src/components/pages/donation_confirmation/DonationCommentPopUp.vue b/src/components/pages/donation_confirmation/DonationCommentPopUp.vue
index 512e8e30e..bd6205456 100644
--- a/src/components/pages/donation_confirmation/DonationCommentPopUp.vue
+++ b/src/components/pages/donation_confirmation/DonationCommentPopUp.vue
@@ -3,9 +3,10 @@
 		<input type="hidden" name="donationId" :value="donation.id"/>
 		<input type="hidden" name="updateToken" :value="donation.updateToken">
 		<div v-if="commentHasBeenSubmitted">
-			<p v-html="$t( serverResponse )"></p>
+			<p class="donation-comment-server-response" v-html="$t( serverResponse )"></p>
 			<FormButton
 				button-type="button"
+				class="donation-comment-return-button"
 				:is-outlined="true"
 				@click="$emit( 'close' )"
 			>
@@ -15,6 +16,7 @@
 		<div v-else>
 			<p>{{ $t( 'donation_comment_popup_explanation' ) }}</p>
 
+			<ScrollTarget target-id="comment-scroll-target"/>
 			<TextField
 				input-type="textarea"
 				v-model="comment"
@@ -22,7 +24,7 @@
 				input-id="comment"
 				placeholder=""
 				:label="$t( 'donation_comment_popup_label' )"
-				:error-message="$t( 'donation_comment_popup_error' )"
+				:error-message="$t( commentError )"
 				:show-error="commentErrored"
 				:autofocus="true"
 			/>
@@ -44,6 +46,18 @@
 				{{ $t( 'donation_comment_popup_is_public' ) }}
 			</CheckboxField>
 
+			<ErrorSummary
+				:is-visible="commentErrored"
+				:items="[
+					{
+						validity: commentErrored ? Validity.INVALID : Validity.VALID,
+						message: $t( commentError ),
+						focusElement: 'comment',
+						scrollElement: 'comment-scroll-target'
+					},
+				]"
+			/>
+
 			<FormSummary :show-border="false">
 				<template #summary-buttons>
 					<FormButton
@@ -66,8 +80,7 @@
 </template>
 
 <script setup lang="ts">
-import { computed, onMounted, ref } from 'vue';
-import axios, { AxiosResponse } from 'axios';
+import { computed, inject, onMounted, ref, watch } from 'vue';
 import { trackDynamicForm, trackFormSubmission } from '@src/util/tracking';
 import { addressTypeFromName, AddressTypeModel } from '@src/view_models/AddressTypeModel';
 import { Donation } from '@src/view_models/Donation';
@@ -75,43 +88,79 @@ import FormButton from '@src/components/shared/form_elements/FormButton.vue';
 import FormSummary from '@src/components/shared/FormSummary.vue';
 import TextField from '@src/components/shared/form_fields/TextField.vue';
 import CheckboxField from '@src/components/shared/form_fields/CheckboxField.vue';
+import { CommentResource } from '@src/api/CommentResource';
+import ErrorSummary from '@src/components/shared/validation_summary/ErrorSummary.vue';
+import { Validity } from '@src/view_models/Validity';
+import ScrollTarget from '@src/components/shared/ScrollTarget.vue';
+
+enum CommentErrorTypes {
+	Empty,
+	Server
+}
 
 interface Props {
 	donation: Donation;
 	addressType: string;
-	postCommentUrl: string;
 }
 
 const props = defineProps<Props>();
-const emit = defineEmits( [ 'disable-comment-link' ] );
+const emit = defineEmits( [ 'disable-comment-link', 'close' ] );
+const commentResource = inject<CommentResource>( 'commentResource' );
 
 const commentForm = ref<HTMLFormElement>( null );
 const comment = ref<string>( '' );
 const commentIsPublic = ref<boolean>( false );
 const commentHasPublicAuthorName = ref<boolean>( false );
 const commentErrored = ref<boolean>( false );
+const commentErrorType = ref<CommentErrorTypes>( CommentErrorTypes.Empty );
 const commentHasBeenSubmitted = ref<boolean>( false );
 const serverResponse = ref<string>( '' );
+const serverError = ref<string>( '' );
 
 const showPublishAuthor = computed<boolean>( () => addressTypeFromName( props.addressType ) !== AddressTypeModel.ANON );
 
-const postComment = (): void => {
+const postComment = (): Promise<void> => {
 	trackFormSubmission( commentForm.value );
-	const jsonForm = new FormData( commentForm.value );
-	axios.post( props.postCommentUrl, jsonForm ).then( ( validationResult: AxiosResponse<any> ) => {
-		if ( validationResult.data.status === 'OK' ) {
-			commentErrored.value = false;
-			commentHasBeenSubmitted.value = true;
-			serverResponse.value = validationResult.data.message;
-			emit( 'disable-comment-link' );
-		} else {
-			commentErrored.value = true;
-		}
+
+	if ( comment.value === '' ) {
+		commentErrorType.value = CommentErrorTypes.Empty;
+		commentErrored.value = true;
+		return;
+	}
+
+	commentResource.post( {
+		donationId: props.donation.id,
+		updateToken: props.donation.updateToken,
+		comment: comment.value,
+		withName: commentHasPublicAuthorName.value,
+		isPublic: commentIsPublic.value,
+	} ).then( ( message: string ) => {
+		commentErrored.value = false;
+		commentHasBeenSubmitted.value = true;
+		serverResponse.value = message;
+		emit( 'disable-comment-link' );
+	} ).catch( ( message: string ) => {
+		commentErrorType.value = CommentErrorTypes.Server;
+		commentErrored.value = true;
+		serverError.value = message;
 	} );
 };
 
 onMounted( trackDynamicForm );
 
+const commentError = computed<string>( () => {
+	if ( commentErrorType.value === CommentErrorTypes.Empty ) {
+		return 'donation_comment_popup_empty_error';
+	}
+	return serverError.value;
+} );
+
+watch( comment, ( newComment: string ) => {
+	if ( commentErrored.value && newComment !== '' ) {
+		commentErrored.value = false;
+	}
+} );
+
 </script>
 
 <style lang="scss">
diff --git a/src/pages/donation_confirmation.ts b/src/pages/donation_confirmation.ts
index 77144f02d..f77f4c6ee 100644
--- a/src/pages/donation_confirmation.ts
+++ b/src/pages/donation_confirmation.ts
@@ -21,6 +21,7 @@ import DonationConfirmation from '@src/components/pages/DonationConfirmation.vue
 import { createFeatureFetcher } from '@src/util/FeatureFetcher';
 import { bucketIdToCssClass } from '@src/util/bucket_id_to_css_class';
 import { ApiCityAutocompleteResource } from '@src/api/CityAutocompleteResource';
+import { ApiCommentResource } from '@src/api/CommentResource';
 
 interface DonationConfirmationModel {
 	urls: { [ key: string ]: string },
@@ -93,5 +94,6 @@ store.dispatch(
 		} );
 	app.use( store );
 	app.provide( 'cityAutocompleteResource', new ApiCityAutocompleteResource() );
+	app.provide( 'commentResource', new ApiCommentResource( pageData.applicationVars.urls.postComment ) );
 	app.mount( '#app' );
 } );
diff --git a/tests/unit/TestDoubles/FakeCommentResource.ts b/tests/unit/TestDoubles/FakeCommentResource.ts
new file mode 100644
index 000000000..97822170a
--- /dev/null
+++ b/tests/unit/TestDoubles/FakeCommentResource.ts
@@ -0,0 +1,16 @@
+import { CommentResource } from '@src/api/CommentResource';
+
+export const successMessage = 'Success';
+export const failureMessage = 'Fail';
+
+export class FakeSucceedingCommentResource implements CommentResource {
+	post(): Promise<string> {
+		return Promise.resolve( successMessage );
+	}
+}
+
+export class FakeFailingCommentResource implements CommentResource {
+	post(): Promise<string> {
+		return Promise.reject( failureMessage );
+	}
+}
diff --git a/tests/unit/components/DonationCommentPopUp.spec.ts b/tests/unit/components/DonationCommentPopUp.spec.ts
index c1c22ec54..e1992a397 100644
--- a/tests/unit/components/DonationCommentPopUp.spec.ts
+++ b/tests/unit/components/DonationCommentPopUp.spec.ts
@@ -1,6 +1,7 @@
 import { mount } from '@vue/test-utils';
 import DonationCommentPopUp from '@src/components/pages/donation_confirmation/DonationCommentPopUp.vue';
 import { AddressTypeModel, addressTypeName } from '@src/view_models/AddressTypeModel';
+import { failureMessage, FakeFailingCommentResource, FakeSucceedingCommentResource, successMessage } from '@test/unit/TestDoubles/FakeCommentResource';
 
 describe( 'DonationCommentPopUp.vue', () => {
 	function getDefaultConfirmationData( isAnonymous: boolean ): any {
@@ -34,6 +35,11 @@ describe( 'DonationCommentPopUp.vue', () => {
 	it( 'displays anyonmous comment toggle for private / company donations', () => {
 		const wrapper = mount( DonationCommentPopUp, {
 			props: getDefaultConfirmationData( false ),
+			global: {
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
+			},
 		} );
 
 		expect( wrapper.find( '#withName' ).exists() ).toBeTruthy();
@@ -42,8 +48,86 @@ describe( 'DonationCommentPopUp.vue', () => {
 	it( 'hides anyonmous comment toggle for anonymous donations', () => {
 		const wrapper = mount( DonationCommentPopUp, {
 			props: getDefaultConfirmationData( true ),
+			global: {
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
+			},
 		} );
 
 		expect( wrapper.find( '#withName' ).exists() ).toBeFalsy();
 	} );
+
+	it( 'shows error when comment is empty', async () => {
+		const wrapper = mount( DonationCommentPopUp, {
+			props: getDefaultConfirmationData( true ),
+			global: {
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
+			},
+		} );
+
+		await wrapper.trigger( 'submit' );
+
+		expect( wrapper.find( '#comment-error' ).exists() ).toBeTruthy();
+		expect( wrapper.find( '.error-summary' ).exists() ).toBeTruthy();
+		expect( wrapper.find( '#comment-error' ).text() ).toStrictEqual( 'donation_comment_popup_empty_error' );
+	} );
+
+	it( 'resets error when comment text is entered', async () => {
+		const wrapper = mount( DonationCommentPopUp, {
+			props: getDefaultConfirmationData( true ),
+			global: {
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
+			},
+		} );
+
+		await wrapper.trigger( 'submit' );
+
+		expect( wrapper.find( '#comment-error' ).exists() ).toBeTruthy();
+		expect( wrapper.find( '.error-summary' ).exists() ).toBeTruthy();
+
+		await wrapper.find( '#comment' ).setValue( 'My super great comment' );
+
+		expect( wrapper.find( '#comment-error' ).exists() ).toBeFalsy();
+		expect( wrapper.find( '.error-summary' ).exists() ).toBeFalsy();
+	} );
+
+	it( 'shows error when API response is rejected', async () => {
+		const wrapper = mount( DonationCommentPopUp, {
+			props: getDefaultConfirmationData( true ),
+			global: {
+				provide: {
+					commentResource: new FakeFailingCommentResource(),
+				},
+			},
+		} );
+
+		await wrapper.find( '#comment' ).setValue( 'My super great comment' );
+		await wrapper.trigger( 'submit' );
+
+		expect( wrapper.find( '#comment-error' ).exists() ).toBeTruthy();
+		expect( wrapper.find( '.error-summary' ).exists() ).toBeTruthy();
+		expect( wrapper.find( '#comment-error' ).text() ).toStrictEqual( failureMessage );
+	} );
+
+	it( 'shows message returned from API', async () => {
+		const wrapper = mount( DonationCommentPopUp, {
+			props: getDefaultConfirmationData( true ),
+			global: {
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
+			},
+		} );
+
+		await wrapper.find( '#comment' ).setValue( 'My super great comment' );
+		await wrapper.trigger( 'submit' );
+
+		expect( wrapper.find( '.donation-comment-server-response' ).text() ).toStrictEqual( successMessage );
+		expect( wrapper.find( '.donation-comment-return-button' ).exists() ).toBeTruthy();
+	} );
 } );
diff --git a/tests/unit/components/pages/donation_confirmation/DonationConfirmation.spec.ts b/tests/unit/components/pages/donation_confirmation/DonationConfirmation.spec.ts
index 6cc21fab6..2c44061da 100644
--- a/tests/unit/components/pages/donation_confirmation/DonationConfirmation.spec.ts
+++ b/tests/unit/components/pages/donation_confirmation/DonationConfirmation.spec.ts
@@ -14,6 +14,7 @@ import {
 } from '@test/data/confirmationData';
 import { addressValidationPatterns } from '@test/data/validation';
 import { DonorResource } from '@src/api/DonorResource';
+import { FakeSucceedingCommentResource } from '@test/unit/TestDoubles/FakeCommentResource';
 
 describe( 'DonationConfirmation.vue', () => {
 	const getWrapper = ( bankData: ConfirmationData, translateMock: ( key: string ) => string = ( key: string ) => key ): VueWrapper<any> => {
@@ -39,6 +40,9 @@ describe( 'DonationConfirmation.vue', () => {
 					$t: translateMock,
 					$n: () => {},
 				},
+				provide: {
+					commentResource: new FakeSucceedingCommentResource(),
+				},
 			},
 		} );
 	};