A partially applied payment will be indicated in the cash receipts register (might just be limited to printing in detail), but it is indicated in the applications total.

I don't know which report is detailed as the "Check Register" as in your example, so it might be helpful to indicate the process you are following and your version, especially sine it appears to contain the multicurrency conversions. That introduces some variations from the standard reporting and registers, but here is one example of the Cash Receipts register in detail where $2800 of a $3280.80 payment was applied without MC.

In normal processing, once the Cash Receipts batch is posted, the unapplied amount can be specifically detailed in the Aged Receivables and AR/Customer Trial Balance reports, Customer Statements, as well as the Customer Status inquiry. There might be more (not sure about the Explorer views), but those are where the data breakout is most obvious.

We are on Sage 500 ERP 2019 Product Update 1 (Version 8.00.1.0).

Our process is we enter the cash receipts in the process cash receipts task under Accounts Receivable activities.  After I've confirmed the total of the batch equals what we've received in our deposit, I click register/post and the following options before posting.

The check register report I mentioned is one of four reports that automatically open up after I've clicked the green proceed button.  I've looked at both the summary and the detail reports and neither one indicates an unapplied amount.

The four reports are:

Accounts Receivable - Cash Receipts Register - Summary (it shows discounts, write-offs, or misc. cash, but not unapplied)

Accounts Receivable - Check Register (previously mentioned) - This report is always blank when I post receipts.

Accounts Receivable - Cash Receipts Register Error Log Listing

Accounts Receivable - Cash Receipts Register - General Ledger Posting Register Summary

I'm trying to avoid having any unapplied amounts.  It would be nice if there was a way to see if any of the receipts are unapplied before they are posted.

I do a periodic review of unapplied funds by going into AR Payments task and searching for any unapplied amounts over $0.01.

It looks like you are reporting in Summary.  If you report in detail, you should see something like Contefication pointed out.  I believe a report will pop out that looks something like:

In this example I applied $4 of the $13 payment.  Had there been no applications, the applications section would be zero.  So it looks like an unapplied amount can be calculated, but there does not seem to be a single unapplied indicator.  My little test was done in the upcoming 2024 release and I am assuming the 2019 version acts the same.

Since the values are in the report, it may be possible to add a visual indicator to the report or a unapplied amount field somewhere, but that would be customization.

I don't think I've ever seen the Check Register in normal processing before, so that's curious. I did notice your batch screen for Process Cash Receipts is missing the Deposit Slip button though. Not sure I've come across a system that isn't integrated with Cash Management but that might account for a difference in the behavior.

You should check the Billing Type in Maintain Customers. You had those AR invoice problems in the past and if you changed your customers to balance forward, then the logic changes for how unapplied payments are handled. You also may want to review the postings in detail, as Ramon suggested.

All of our customers are setup with open item billing type. I'm going to start reviewing the cash receipt detail report as you and Ramon pointed out.