Hi Karen57,
Welcome to the UK Community for QuickBooks Online, it's great to have you here.
The good thing about QuickBooks Online (QBO) is that it will allow you to change the Start Date of your VAT return if it's your first time preparing it. With this, you'll be able to include the relevant backdated purchases and get the data you're looking for. Click on Submit Return, and then change the date ranges to meet what you want it to.
Just a heads up, QBO uses the data based on your registration with HMRC. That said, if you didn't include the backdated info on your registration, it would be a good idea to manually file this through the HMRC portal.
In addition, to make sure that you won't be filing this twice, you can mark the return in QBO as filed. The steps below will guide you through the entire process:
Prepare VAT returns in QuickBooks Online
- Click Taxes in the left navigation menu.
- Go to the VAT tab.
- In the Open returns section, select Submit return.
- Edit the Start Date to when you wanted to start charging for VAT and then enter the End Date.
- Click the Submit to HMRC drop-down button, then choose Mark as filed.
- Hit Continue.
I'm also including this article for additional insight about this: VAT: Getting Started
That should get you going in the right direction.
