A question that we frequently get asked is how to run a retrospective aged debtor or creditor report in Sage 200, this blog will show you how.
I will go through running an aged debt report but it same logic applies to run an aged credit report.
Bring up the sales aging report as normal – Sales, Reports, Credit Control, Aged Debtors

Without changing any other criteria you need to tick the box called “Retrospective” as indicated above and then select the date that you want the report to run at in “base date for ageing”.
In the above example the date is set to 31 Dec 2009, so by selecting retrospective this will run a report as if it had been run on 31st Dec 2009, which means it will only include transactions, invoices, credits, receipts etc plus allocations dated before 31st Dec 2009.
Should the report not equal your expected value, for example agreeing to the nominal, then what has probably happened is that you have a payment or receipt date that is different to the allocation date of that receipt or payment. This is especially common on the purchase ledger if a payment run is made prior to a month end and the transaction is dated for the next month, the allocation will be in one month and the payment in the next so there is a reconciliation difference of that amount.
Allocation dates are shown at the top of the payment/receipt allocation screens, pictured below