Hi there, SNBUXANI.
Thank you for posting here in QuickBooks Community and I'm always here to help you.
Yes, the provided steps above are the solutions found why the XXXX display in the Vat number. If the issue continues to occur, I suggest contacting our QuickBooks Support Team. They have the tools to pull up your account and to further dig deeper into finding the root cause of this issue.
Here's how to contact them:
1. Open your QuickBooks Account.
2. At the top right, click the Help icon.
3. Click Contact Us.
4. Under What can we help you with?, enter your concern about XXXX that shows in the vat number.
5. Click Let's Talk.
6. You'll be routed into the Choose a way to connect with us page.
- Start a chat with a support expert.
- Get a callback from the next available expert.
7. Select how you want to contact them and fill in the information.
Please check this article on how QuickBooks Online allows you to remove a VAT or GST rate if you no longer use it: Remove a VAT or GST rate.
Please know that you're always welcome to post if you have any other concerns. Wishing you and your business continued success.