Are you also adjusting inventory / recording cost of goods sold as part of your daily cash sale entry?

If NO, then you could just record the entry through General Journal rather than Sales Journal.

If YES, then you could do it in 2 steps.  Step 1, record the entry through the Sales Journal, as you have been doing.  Step 2.  Record a General Journal entry to split up Mastercard, Visa, etc.  The entry would be Dr Cash (mastercard amount), Dr Cash (Visa amount), etc., all offset by Cr cash (total deposit).  So, no net effect to Cash, but your money sources are now divided up so your bank rec will work better.

Thank you for your suggestions.  Our daily sales are related to a particular event, so the Sales Journal allows me to track sales for the event using the customer field. Our volume is not high, so I'll continue to muddle through the bank reconciliation.  However It seems to me that if a user goes to the trouble to enter multiple line items for the one account, Sage should just post what's entered.

Subjournals like Sales are always grouped together.  The General Journal keeps a good record of individual entries to the same account multiple times in the same entry.  However, because you wish to track things under a specific customer you have to fool the system a little.  This isn't perfect but an alternative.

The issue is using the same account.  So don't use the same account.

When you have an entry like

Sales         $1000        4200 Event Sales

MC Pmt     -$50           1060 Bank

VISA Pmt   -$75           1060 Bank

Debit Pmt   $-100         1060 Bank

Cash Pmt    $-775        1060 Bank but done through the Receipts module

You can do two possible things, one or the other.

Post all payments in the Receipts module.

Or

do the entry like this

Sales         $1000        4200 Event Sales

MC Pmt     -$50           1082 MC Receivable

VISA Pmt   -$75           1080 VISA Receivable

Debit Pmt   $-100         1060 Bank

Cash Pmt    $-775        1060 Bank but done through the Receipts module

This does require a general journal entry to post the MC and VISA to the bank when you see that it is deposited.

A final alternative may be to post the entry in the General Journal and use a Project to track what you wish to track.

Thank you for your suggestions.  They've given me some ideas to play with.