If the UK ETA app is not accepting your address, follow these steps for troubleshooting:

1. Verify Address Format: Make sure you are entering your address in the required format exactly as specified by the app. Pay attention to any specific formatting rules, such as not including extra spaces or using the correct abbreviations for street types (e.g., St. for Street).

2. Check for Common Issues:
- Correct Country Selection: Ensure you have selected the correct country for your address.
- No Special Characters: Avoid using any special characters that may not be accepted by the app.
- Address Components: Verify that every component of your address (house number, street name, city, postal code, and country) is filled in correctly.

3. Update the App: Ensure you have the latest version of the UK ETA app installed. An outdated app may have bugs that affect functionality.

4. Clear Cache: If the app allows it, try clearing its cache. This may help resolve any temporary glitches.

5. Try a Different Device or Browser: If possible, try to access the app from a different device or browser to see if the issue persists.

6. Restart the App: Close the app completely and reopen it. This simple step can sometimes resolve minor issues.

7. Check Internet Connection: A stable and reliable internet connection is essential for the app to function correctly. Ensure you are connected to the internet.

8. Consult Official Resources: If the problem persists, refer to the official guide on using the app, which may have specific troubleshooting steps - learn more.

9. Seek Help: If none of the above solutions work, consider reaching out to the UK ETA support team directly for assistance or check community forums for others who may have had similar issues - learn more.

By following these steps, you should be able to resolve the issue with your address not being accepted in the UK ETA app.