How much history to migrate and how much to archive

Loading ten years of invoices feels safe, yet it slows the load, complicates reconciliation and fills the new system with duplicate customers, dormant suppliers and retired item codes. Ask one question of each record type.

Will the system fail tomorrow without it? If yes, the record migrates. If staff only look it up now and then, it goes to the archive, and if neither applies it becomes a deletion candidate once the retention rules allow.

Ask the people who use each record. The warehouse lead knows which batch histories matter in a recall, the credit controller knows which ageing reports reach back, and the payroll clerk knows which leave cards matter.

Master data comes first, because without customers, suppliers, items, tax codes and a chart of accounts nothing can be posted, and every later import checks its references against them. Next, load anything still open. The next payment, credit note, delivery or batch transfer depends on a record that has not yet closed, and the old system will not be there to finish it.

The current financial year’s transactions usually come across too, since debtor ageing, sales by customer and stock movement by item all draw on them. Without that year, the first monthly report has nothing to compare against, and the finance team will ask where the history went.

Closed years rarely change. Paid invoices, cancelled orders, old quotations and bank statements only need to be found, so keep them in a read-only database or indexed PDFs. Index them by customer, document number and date.

Back it up and name an owner. The test is plain: a clerk should find a four-year-old invoice, with its signed proof of delivery attached, in under a minute. Time it.

Pick the format for the long term. PDFs open on any computer, while a database dump needs a compatible program years from now, so write down which program and which version reads the archive.

Tax and company law set minimum retention periods, and they differ by country and by record type, so your accountant should confirm which ones apply to your business. This is guidance, not legal advice.

Retention has an upper limit too. Personal data such as employee bank details, leave cards and customer contact lists can breach privacy rules when held without a reason, and customers may ask for deletion. Write down the retention period for each record type and the earliest date it can be removed, then set a yearly reminder so the list stays current.

Keep the signed grid for auditors. If a tax officer asks why older invoices are missing from the live system, the signed grid and the archive test results answer the question in one reply.

Put the scope in one grid. Finance signs it. Run a dry load of the chosen data, then compare closing balances against the old ledger account by account, along with debtor ageing and stock valuation. Chase every difference back to a missing opening balance, a wrong cut-off date or a record loaded twice, before anyone signs the load as complete.

Test the archive with five real lookups chosen by the people who answer customer queries, and record how long each one took and who found it. Ask for the retention list this week. Then attach it to the scope grid.