Thanks for visiting us here today. I'll share some information about the VAT field in invoices. This field, will only auto-fill the VAT codes or rates, it doesn't includes the client's VAT number.
On the other hand, I'll be taking note of this feature so our Developers will know that this is something they need to consider adding. Rest assured, they are working non-stop to enhance the product and deliver the best experience for all QuickBooks users.
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For more related articles and videos about VAT, browse this link to go to the page. It has our general VAT topics to guide you along: Manage Taxes in QuickBooks.
I'm just a comment away if you have other questions about VAT. Don't hesitate to reply. Stay safe.