I have recorded a VAT payment twice, if I undo the transaction I have 2 records that match but dont know how to delete 1 of them. Please help.

Hello there, @beatyourleak.

In QuickBooks Online (QBO), all your VAT information is recorded in the Taxes menu. When you manually recorded the VAT payment, you can delete one through the Payments section from the Taxes menu. Here's how:

1. Go to the Taxes menu.
2. Select the Payments tab.
3. Find the payment you want to delete, then click the drop-down arrow under the Action column and choose Delete.
4. Choose Yes to confirm.

I've attached a screenshot that shows the first three steps.

However, in case you no longer see the Delete option, I'd recommend contacting our Customer Care team. They can securely pull up your account and delete the payment for you. this way, you're able to match only one payment to your bank transaction.

We've updated our support options in QBO. You'll have to request a callback to talk to one of our representatives. Here's how:

1. Go to the Help menu.
2. Choose Contact Us. 
3. Enter your specific concern in the What can we help you with? box. 
4. Click Let's talk. 
5. Select Get a callback. 
6. Enter your contact details. 
7. Hit Confirm my call. 

I've attached a screenshot below for your reference.

In the meantime, I'm adding this article to further guide you in effectively monitoring your taxes in QBO: Manage taxes in QuickBooks. It includes topics about VAT, tax reports, and MTD to name a few.

Please know that you're welcome to comment below if you have other concerns or follow-up inquiries about recording VAT payment in QBO. I'm just around to help. Take care always.