Why will qb not authorize my bank account is it because i down graded to £20 p/m ?

Hello, info1441.

I take it that you're trying to connect your bank. In this case, there are several reasons why QuickBooks is unable to authorise it. I'll provide the details and help you resolve the issue. 

The subscription plans offer the same Online Banking features. Downgrading your plan won't affect the connection. There might be an ongoing maintenance from the bank. This can affect the connection and authorisation process, so you'll want to reach out to them for confirmation.

After the maintenance update, connect and authorise your bank again for the Online Banking feature. 

If that's not the case, did you encounter a specific error message during the authorisation process? This article has the steps and details on how to fix it: Open Banking connection errors.

Another reason is that your bank doesn't support the Open Banking feature. You can check this article for a list of supported and unsupported banks: Understanding if you can connect your bank feeds to Open Banking.

If ever your bank doesn't support the feature, you'll want to manually upload your transactions. 

After connecting your bank or bringing in your transactions, you can start using the Banking feature. Simply go to the Banking page to begin.

Next, start managing your downloaded transactions by categorising, matching or adding them to your books. 

Finally, you can start your regular bank reconciliation. I recommend reading this article for a guide about the workflow: Reconcile an account in QuickBooks Online.

I'm still open to answer any other questions you might have for QuickBooks. Just post the details here and I'll get back to this thread as soon as possible.