We're unable to turn off the VAT feature once enabled, @Manchester. Not to worry, I've got a workaround for you.
Disabling VAT within the program affects the accounts and transactions. That said, let's change the default tax rate selection to No VAT. It won't post anything to your VAT center for you to submit to HMRC.
Here's how:
Go to the Gear icon and select Account and Settings.
Press the Advanced tab, then click Accounting.
On the Default tax rate selection, choose No VAT from thedrop-down