diff --git a/editor.planx.uk/src/@planx/components/FindProperty/Public/Autocomplete.tsx b/editor.planx.uk/src/@planx/components/FindProperty/Public/Autocomplete.tsx
index 9dc263a464..f6e53b8290 100644
--- a/editor.planx.uk/src/@planx/components/FindProperty/Public/Autocomplete.tsx
+++ b/editor.planx.uk/src/@planx/components/FindProperty/Public/Autocomplete.tsx
@@ -10,6 +10,7 @@ import find from "lodash/find";
 import { parse, toNormalised } from "postcode";
 import React, { useEffect, useState } from "react";
 import InputLabel from "ui/public/InputLabel";
+import ErrorWrapper from "ui/shared/ErrorWrapper";
 import Input from "ui/shared/Input";
 
 import type { SiteAddress } from "../model";
@@ -25,6 +26,12 @@ interface PickOSAddressProps {
   initialSelectedAddress?: Option;
   id?: string;
   description?: string;
+  showPostcodeError: boolean;
+  setShowPostcodeError: React.Dispatch<React.SetStateAction<boolean>>;
+  addressAutocompleteError?: string;
+  setAddressAutocompleteError: React.Dispatch<
+    React.SetStateAction<string | undefined>
+  >;
 }
 
 const AutocompleteWrapper = styled(Box)(({ theme }) => ({
@@ -55,7 +62,6 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
   const [selectedOption, setSelectedOption] = useState<Option | undefined>(
     props.initialSelectedAddress ?? undefined,
   );
-  const [showPostcodeError, setShowPostcodeError] = useState<boolean>(false);
 
   // Fetch blpu_codes records so that we can join address CLASSIFICATION_CODE to planx variable
   const { data: blpuCodes } = useQuery(FETCH_BLPU_CODES, {
@@ -109,6 +115,7 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
           ), // display value shown on PropertyInformation, should match <address-autocomplete /> options formatting
           source: "os",
         });
+        props.setAddressAutocompleteError(undefined);
       }
     };
 
@@ -124,7 +131,7 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
   }, [sanitizedPostcode, selectedOption]);
 
   const handleCheckPostcode = () => {
-    if (!sanitizedPostcode) setShowPostcodeError(true);
+    if (!sanitizedPostcode) props.setShowPostcodeError(true);
   };
 
   // XXX: If you press a key on the keyboard, you expect something to show up on the screen,
@@ -135,7 +142,7 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
     if (selectedOption) {
       // Reset the selected address on change of postcode to ensures no visual mismatch between address and postcode
       setSelectedOption(undefined);
-      // Disable the "Continue" button if changing postcode before selecting new address after having come "back"
+      // Invalidate the "Continue" button if changing postcode before selecting new address after having come "back"
       props.setAddress(undefined);
     }
 
@@ -160,7 +167,7 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
           id="postcode-input"
           value={postcode || ""}
           errorMessage={
-            showPostcodeError && !sanitizedPostcode
+            props.showPostcodeError && !sanitizedPostcode
               ? "Enter a valid UK postcode"
               : ""
           }
@@ -174,7 +181,7 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
             maxLength: 8,
             "aria-describedby": [
               props.description ? DESCRIPTION_TEXT : "",
-              showPostcodeError && !sanitizedPostcode
+              props.showPostcodeError && !sanitizedPostcode
                 ? `${ERROR_MESSAGE}-${props.id}`
                 : "",
             ]
@@ -184,16 +191,21 @@ export default function PickOSAddress(props: PickOSAddressProps): FCReturn {
         />
       </InputLabel>
       {sanitizedPostcode && (
-        /* @ts-ignore */
-        <address-autocomplete
-          id="address-autocomplete"
-          data-testid="address-autocomplete-web-component"
-          postcode={sanitizedPostcode}
-          initialAddress={selectedOption?.title || ""}
-          osProxyEndpoint={`${process.env.REACT_APP_API_URL}/proxy/ordnance-survey`}
-          arrowStyle="light"
-          labelStyle="static"
-        />
+        <ErrorWrapper
+          error={props.addressAutocompleteError}
+          id={"address-autocomplete"}
+        >
+          {/* @ts-ignore */}
+          <address-autocomplete
+            id="address-autocomplete"
+            data-testid="address-autocomplete-web-component"
+            postcode={sanitizedPostcode}
+            initialAddress={selectedOption?.title || ""}
+            osProxyEndpoint={`${process.env.REACT_APP_API_URL}/proxy/ordnance-survey`}
+            arrowStyle="light"
+            labelStyle="static"
+          />
+        </ErrorWrapper>
       )}
     </AutocompleteWrapper>
   );
diff --git a/editor.planx.uk/src/@planx/components/FindProperty/Public/Public.test.tsx b/editor.planx.uk/src/@planx/components/FindProperty/Public/Public.test.tsx
index 7e5dee7686..cb6e25089d 100644
--- a/editor.planx.uk/src/@planx/components/FindProperty/Public/Public.test.tsx
+++ b/editor.planx.uk/src/@planx/components/FindProperty/Public/Public.test.tsx
@@ -159,8 +159,14 @@ describe("render states", () => {
     expect(autocomplete.getAttribute("postcode")).toEqual("SE5 0HU");
     expect(autocomplete.getAttribute("initialAddress")).toBeFalsy();
 
-    // expect continue to be disabled because an address has not been selected
-    expect(screen.getByTestId("continue-button")).toBeDisabled();
+    // user is unable to continue and to submit incomplete data
+    const continueButton = screen.getByTestId("continue-button");
+    expect(continueButton).toBeEnabled();
+    await user.click(continueButton);
+
+    expect(
+      screen.getByTestId("error-message-address-autocomplete"),
+    ).toBeInTheDocument();
     expect(handleSubmit).not.toHaveBeenCalled();
   });
 
@@ -233,7 +239,11 @@ describe("render states", () => {
       await screen.findByText("Type your postal code"),
     ).toBeInTheDocument();
 
-    expect(screen.getByTestId("continue-button")).toBeDisabled();
+    // user is unable to continue and submit incomplete data
+    expect(screen.getByTestId("continue-button")).toBeEnabled();
+    await user.click(screen.getByTestId("continue-button"));
+
+    expect(screen.getByText("Enter a valid UK postcode")).toBeInTheDocument();
     expect(handleSubmit).not.toHaveBeenCalled();
   });
 
@@ -316,11 +326,14 @@ describe("picking an OS address", () => {
   });
 
   it("updates the address-autocomplete props when the postcode is changed", async () => {
+    const handleSubmit = jest.fn();
+
     const { user } = setup(
       <MockedProvider mocks={findAddressReturnMock} addTypename={false}>
         <FindProperty
           description="Find your property"
           title="Type your postal code"
+          handleSubmit={handleSubmit}
         />
       </MockedProvider>,
     );
@@ -351,7 +364,13 @@ describe("picking an OS address", () => {
 
     // User is unable to continue and to submit incomplete data
     const continueButton = screen.getByTestId("continue-button");
-    expect(continueButton).toBeDisabled();
+    expect(continueButton).toBeEnabled();
+    await user.click(continueButton);
+
+    expect(
+      screen.getByTestId("error-message-address-autocomplete"),
+    ).toBeInTheDocument();
+    expect(handleSubmit).not.toHaveBeenCalled();
   });
 
   it("recovers previously submitted address when clicking the back button", async () => {
diff --git a/editor.planx.uk/src/@planx/components/FindProperty/Public/index.tsx b/editor.planx.uk/src/@planx/components/FindProperty/Public/index.tsx
index 10bdab7330..6be079f44e 100644
--- a/editor.planx.uk/src/@planx/components/FindProperty/Public/index.tsx
+++ b/editor.planx.uk/src/@planx/components/FindProperty/Public/index.tsx
@@ -51,9 +51,13 @@ function Component(props: Props) {
       : "os-address";
   const [page, setPage] = useState<"os-address" | "new-address">(startPage);
 
+  const [showPostcodeError, setShowPostcodeError] = useState<boolean>(false);
+  const [addressAutocompleteError, setAddressAutocompleteError] =
+    useState<string>();
   const [mapValidationError, setMapValidationError] = useState<string>();
   const [showSiteDescriptionError, setShowSiteDescriptionError] =
     useState<boolean>(false);
+  const [dataFetchError, setDataFetchError] = useState<string>();
 
   const [address, setAddress] = useState<SiteAddress | undefined>(
     previouslySubmittedData?._address,
@@ -111,7 +115,16 @@ function Component(props: Props) {
   }, [data, address]);
 
   const validateAndSubmit = () => {
-    // TODO `if (isValidating)` on either page, wrap Continue button in error mesage?
+    if (isValidating) {
+      setDataFetchError("Please wait for data fetching to complete");
+    }
+
+    if (page === "os-address") {
+      if (address?.postcode === undefined) setShowPostcodeError(true);
+
+      if (address?.title === undefined)
+        setAddressAutocompleteError("Select an address");
+    }
 
     if (page === "new-address") {
       if (address?.x === undefined && address?.y === undefined)
@@ -155,11 +168,8 @@ function Component(props: Props) {
   return (
     <Card
       handleSubmit={validateAndSubmit}
-      isValid={
-        page === "new-address" && !isValidating
-          ? true
-          : Boolean(address) && !isValidating
-      }
+      isValid={true}
+      error={dataFetchError}
     >
       {getBody()}
     </Card>
@@ -190,7 +200,7 @@ function Component(props: Props) {
           />
           {Boolean(address) && isValidating && (
             <DelayedLoadingIndicator
-              msDelayBeforeVisible={50}
+              msDelayBeforeVisible={0}
               text="Fetching data..."
             />
           )}
@@ -216,6 +226,10 @@ function Component(props: Props) {
             }
             id={props.id}
             description={props.description || ""}
+            showPostcodeError={showPostcodeError}
+            setShowPostcodeError={setShowPostcodeError}
+            addressAutocompleteError={addressAutocompleteError}
+            setAddressAutocompleteError={setAddressAutocompleteError}
           />
           {!props.allowNewAddresses ? (
             <ExternalPlanningSiteDialog
@@ -238,7 +252,7 @@ function Component(props: Props) {
           )}
           {Boolean(address) && isValidating && (
             <DelayedLoadingIndicator
-              msDelayBeforeVisible={50}
+              msDelayBeforeVisible={0}
               text="Fetching data..."
             />
           )}
diff --git a/editor.planx.uk/src/@planx/components/shared/Preview/Card.tsx b/editor.planx.uk/src/@planx/components/shared/Preview/Card.tsx
index 6eb6ba8dda..96b340db24 100644
--- a/editor.planx.uk/src/@planx/components/shared/Preview/Card.tsx
+++ b/editor.planx.uk/src/@planx/components/shared/Preview/Card.tsx
@@ -7,6 +7,7 @@ import { useAnalyticsTracking } from "pages/FlowEditor/lib/analytics/provider";
 import { useStore } from "pages/FlowEditor/lib/store";
 import React, { useEffect } from "react";
 import { ApplicationPath } from "types";
+import ErrorWrapper from "ui/shared/ErrorWrapper";
 
 import SaveResumeButton from "./SaveResumeButton";
 
@@ -14,6 +15,7 @@ interface Props {
   children: React.ReactNode;
   isValid?: boolean;
   handleSubmit?: (data?: any) => void;
+  error?: string;
 }
 
 export const contentFlowSpacing = (theme: Theme): React.CSSProperties => ({
@@ -78,20 +80,21 @@ const Card: React.FC<Props> = ({
           {...props}
         >
           {children}
-
           <Box pt={2}>
             {handleSubmit && (
-              <Button
-                variant="contained"
-                color="prompt"
-                size="large"
-                type="submit"
-                disabled={!isValid}
-                onClick={async () => await handleSubmit()}
-                data-testid="continue-button"
-              >
-                Continue
-              </Button>
+              <ErrorWrapper error={props.error} id="continue-button">
+                <Button
+                  variant="contained"
+                  color="prompt"
+                  size="large"
+                  type="submit"
+                  disabled={!isValid}
+                  onClick={async () => await handleSubmit()}
+                  data-testid="continue-button"
+                >
+                  Continue
+                </Button>
+              </ErrorWrapper>
             )}
             {showSaveResumeButton && <SaveResumeButton />}
           </Box>