A reconciliation shows a difference between a subledger and the GL for a period that has been closed.
Most likely causes
- Transactions were accounted but not transferred. Accounting creates entries; transfer moves them to the GL. A difference equal to a clean set of transactions usually means this.
- Journals are transferred but unposted. They exist in the GL and do not affect balances until posted.
- Something was posted directly to a control account. A manual journal against an account the subledger owns will never reconcile, and this is worth ruling out early because it changes who needs to fix it.
- The comparison spans different currencies or ledgers. Entered versus accounted amounts diverge whenever a rate is involved.
What to check
- Whether the difference is one round number or many small ones. One suggests a single journal; many suggests a batch that did not transfer.
- Unposted journal batches for the period, before anything else.
- Manual journals touching subledger control accounts in that period.
- That both sides of the comparison use the same ledger, currency basis, and date range — mismatched criteria produce most "impossible" differences.
Care required
Reopening a closed period has downstream effects on reporting that has already been issued. Establish the cause before changing the period status.
If none of the above explains it, raise a ticket and include what you checked. Reading this article cost you no hours.