I am unable to change my vat nr. it changes in settings but not on the invoices. what am i doing wrong?

It's good that you're able to update the VAT number in the settings, craffordshaun7.

In QuickBooks Online, we can only add the Business (CIPC) Reg. No. It seems that you're using a custom field to include the VAT number. If so, we can just manually change it when creating an invoice. 

In addition, you can follow these steps if you entered the VAT number in the Business (CIPC) Reg. No. field:

1. Go to the Gear icon and select Custom Form Styles.
2. Locate the invoice template and click Edit.
3. Select the Content tab and click on the header section of the invoice.
4. In the Business (CIPC) Reg. No. field, update the number.
5. Click Done to save it.

Once done, let's create another invoice again. This article will serve as your guide in customizing your i invoices, quotes and sales receipts in QuickBooks Online.

Here's another article I want to share. This will walk you through the process in recording customer payments:

• Record invoice payments

Comment below if you need anything else. Have a great day!