Quiet expected upgrade-preview 400s in Sentry

client/utilities/hooks/useUpgradePreview.ts

@@ -55,6 +55,13 @@ export const useUpgradeProduct = () => {
 				isTestUser,
 			});
 
+			if (previewResponse === null) {
+				setPreviewError(
+					'You are not currently eligible for an upgrade online. Please contact customer care to discuss your options.',
+				);
+				return;
+			}
+
 			setMainPlan(mainPlan);
 			setSubscription(subscription);
 			setPreviewResponse(previewResponse);

client/utilities/hooks/useUpgradeProductLoader.ts

@@ -103,6 +103,11 @@ export const useUpgradeProductLoader = (): LoaderState => {
 					isTestUser: productDetail.isTestUser,
 				});
 
+				if (preview === null) {
+					setState({ isLoading: false, shouldRedirect: true });
+					return;
+				}
+
 				setMainPlan(fetchedMainPlan);
 				setSubscription(productDetail.subscription);
 				setPreviewResponse(preview);

client/utilities/productUtils.ts

@@ -278,7 +278,7 @@ export const changePlanFetch = ({
 export const fetchUpgradePreviewData = async (params: {
 	subscriptionId: string;
 	isTestUser: boolean;
-}): Promise<UpgradePreviewResponse> => {
+}): Promise<UpgradePreviewResponse | null> => {
 	const response = await changePlanFetch({
 		subscriptionId: params.subscriptionId,
 		isTestUser: params.isTestUser,
@@ -287,6 +287,13 @@ export const fetchUpgradePreviewData = async (params: {
 		preview: true,
 	});
 
+	// A 400 means the user is ineligible for an online upgrade.
+	// Treat as "no preview available" rather than an error to avoid
+	// spurious Sentry noise for an expected business condition.
+	if (response.status === 400) {
+		return null;
+	}
+
 	if (!response.ok) {
 		throw new Error(`Failed to fetch upgrade preview: ${response.status}`);
 	}