The difference between these three VAT codes in QuickBooks Online comes down to whether VAT applies at all, and whether the transaction appears on your VAT return.
0% / Zero Rate (Z)
Used for goods and services that are taxable, but the VAT rate charged is 0%. or example, children's clothing, footwear, or leaflet printing. These transactions do appear on your VAT return: the net amount posts to Box 6 (sales) or Box 7 (purchases), with £0 VAT recorded in Box 1 or Box 4.
Exempt
Used for goods and services that fall under special categories where VAT legally cannot be charged at all. For example, insurance, medical treatments, or education. Like Zero Rate, the net amount still posts to Box 6 or Box 7 on your VAT return, but no VAT amount is ever calculated, because these items sit outside the VAT system entirely.
No VAT
Used when a transaction is completely out of scope for VAT.Most commonly because you're not VAT-registered, the purchase isn't part of your VAT-registered business, or it involves goods/services outside the UK or EU. Unlike the two codes above, No VAT does not post to your VAT return at all — not even to Box 6 or 7.
Which one applies to your situation?
QuickBooks Support and Community can't tell you which code to use for a specific transaction. That depends on the nature of the goods/services and your VAT registration status, which is accounting advice specific to your business. For example, whether a purchase from a non-VAT-registered supplier should be Zero Rated, Exempt, or excluded via No VAT depends on the specifics of what was purchased. It's worth confirming with your accountant or checking HMRC's guidance on VAT rates if you're unsure.
Full breakdown of all VAT codes: Understanding VAT codes in QuickBook