Six problems
All of them are record-keeping problems
None of these is caused by the accounting being wrong. They are caused by the working around it living in workbooks, inboxes and the heads of people who move on.
The reconciliations are done once a year, under pressure
A reconciliation performed monthly is a control; the same one performed in March is an archaeology exercise. Carry-forward on the row fingerprint is what makes monthly worth doing: an item outstanding at the end of one period appears in the next pointing at its predecessor and keeping its original period, so closing this month does not mean re-deriving last month.
Nobody can say how old the outstanding items actually are
Because the workbook is rebuilt each period and everything looks new. Here an item keeps the period it was first raised in, so an ageing means what it says — and a stale item is visible as stale months before somebody has to explain it to an auditor.
The explanation for a written-off difference is in an email
It is a required field here, in the schema. Clearing an item without a narration is not possible, so the reason is on the record next to the amount rather than in somebody’s inbox. That is a control for you before it is evidence for the auditor.
The credit reconciliation and the return disagree
The purchase register is reconciled against the portal statement invoice by invoice, with missing, excess and tax mismatches reported separately rather than netted into one difference, and ineligible credit disallowed with the provision cited on the line. The figures the reconciliation produces are the figures, computed once in exact decimals — there is no second spreadsheet to reconcile the reconciliation against.
The auditor asks where a number came from and it takes a day
Every figure in a deliverable traces to a computation line, its working paper and the ledger row it was imported from, and that trail is stored rather than reconstructed. The answer to "where did this come from" is a click, and the same trail is what your auditor uses rather than a fresh set of questions.
A month closed with a small difference and it was written off
That is the habit worth breaking, and it usually starts with software that never quite ties. Exact decimals mean a reconciliation that should be zero is zero, so a difference of a few paise is a real difference rather than an arithmetic artefact — and the cross-foot runs on every table before anything is produced from it.