How do I change the VAT period opened

You're unable to change the VAT period, emmaowusu. I'm happy to give you more details about this.

The way the system works is that it will show you VAT starting from the oldest period, so you can file and pay for it before seeing your VAT in the next period. It is designed in such a way that you don't miss the filing and paying your tax.

Your VAT settings will also determine which period to show first. For example, if you set the starting month as January and your filing frequency as Quarterly, the first's quarter's VAT will show up first.

If you're new to QuickBooks, and you entered transactions in the previous period in which you filed and paid your taxes, just mark the return as filed and record your payment. Please note the option to record a payment comes after marking your return as filed.

1. On the VAT page, select Prepare return (of the previous period). 
2. Enter the Submission date. The actual date you filed that return.
3. In the lower-right corner, click the down arrow next to Submit to HMRC.
4. Select Mark as filed.

You can check out the references for QBO. Just select the VAT topic. We also have a test-drive account where you can try everything before working on your QBO company.

If you have other questions about taxes, please don't hesitate to go back to this thread.