Entering payments received in bank to outstanding invoices, is it just a case of going to invoice and making payment to bank account? will the match up?

I can summarize the most important discussions on this thread for you, Jonboy1210.

Accounts Receivable (A/R) is an asset account used for most regions. In the UK region, Debtors is the corresponding account for it. That is the reason you can't see it from your Chart of Account list.  Therefore, there's no need for your to pull up a report to show when the account has been named. 

Here's what will happen when you add deposits from the Banking page to an open invoice.

QuickBooks Online will allows you to use the Find match function for bank deposits to be able to add them to an open invoice. Once they are added, the invoice's balance reduces. 

Let say for example, I have an invoice for 1,000 pound. 

When partial bank deposits are downloaded, use the Find match function to add these deposits one by one.

In the Match transactions page, expand the date range and choose All from the Show drop-down to see the open invoice. Select the invoice and click on Save.

To view if the payment was posted, please open the invoice. The deposit added from the Banking page is already posted to the bank account, and the invoice balance reduces. You don't need to make any receive payment transactions or link the deposits. 

I'm pretty sure after following the screenshots above you're all caught up. 

We are happy in helping you with your other concerns. Just go ahead and post them here.