I want to change my old vat nuber to a new one

You've come to the right place, rdebruinf.

I'd be happy to guide you in changing your old VAT number to a new one. To do this, you can go to the Account and settings page. Let me show you the step-by-step process:

1. Go to the Gear icon at the top.
2. Choose Accounts and settings.
3. In the left menu, select Company.
4. Go to the Company name section and click ✎ Edit.
5. Edit your VAT # in the field provided.
6. Select Save, then click Done.

That's it! Your VAT number is now updated.

If you want to make changes to other company information in the future, you can refer to this article: Change your company name, contact info, or VAT # in QuickBooks Online.

Please don't hesitate to let me know if you have any additional questions or concerns about updating your VAT number. I am always here to help. Have a great day ahead!