Switching accounting software is an accounting handover as well as a technical task. A successful import can still leave missing invoices, duplicate sales, incorrect VAT or balances nobody can explain. The aim is to establish a reliable starting position while preserving the evidence behind earlier periods.
In this article
- Back up and export existing records
- Agree a switch date and migration scope
- Check opening balances and imported data
- Test reports before relying on the new system
Treat the move as a small project with a named owner, cut-off date and acceptance checks. Agree who extracts the old data, maps it, imports it and reviews the results. Allow time to resolve differences before relying on the new reports.
Decide how much history you need to move
There are three common approaches: bring across detailed transaction history; import selected recent periods; or start with opening balances and outstanding items while keeping an accessible archive. Each has trade-offs.
Detailed history offers continuity but may be harder to map correctly. Opening balances can simplify setup, but users must understand where to find earlier documents and how old balances will settle. Decide based on reporting needs, transaction volume, VAT arrangements and the quality of the old data.
Do not delete records because importing them is inconvenient. GOV.UK explains the company accounting records that must be retained. Retention requirements depend on the records and circumstances, so confirm your archive plan for tax, payroll and other documents separately.
Reconcile before you export
The migration date is not an opportunity to bury unexplained differences. Reconcile bank accounts, payment processors, customer and supplier balances, loans, payroll control accounts and VAT. Identify suspense balances and ask what they represent.
Save a final trial balance and supporting schedules for the cut-off date. Record which periods are finalised and which remain subject to year-end adjustments. If an accountant later changes an old period, decide how the corresponding opening balance correction will reach the new system.
| Control total | Compare before and after migration |
|---|---|
| Bank | Reconciled balance and outstanding transactions |
| Customers | Total debtors and every unpaid invoice |
| Suppliers | Total creditors and every unpaid bill |
| VAT | Ledger balance, submitted returns and unsettled amounts |
| Payroll | Amounts owed to employees, HMRC and pension providers |
| Assets and loans | Supporting schedules and opening ledger entries |
A balanced trial balance is necessary, but insufficient. Equal debits and credits do not prove that customers, tax codes or transaction dates are correct.
Build an archive you can actually use
Export the general ledger, trial balances, financial reports, sales and purchase listings, bank reconciliations and audit history where available. Download attachments and filed-return evidence. Record the extraction date and whether the files cover all periods.
Open a selection of archived invoices and test a search for a specific customer balance. Store files securely with appropriate access and a backup. Find out whether cancelling the old subscription removes document access or prevents further exports; obtain the answer before cancellation.
For VAT records, HMRC sets out digital-record and software requirements. Check that the transition preserves the required records and any applicable digital links. A folder of PDF invoices alone does not settle every MTD requirement.
Map transactions and tax settings deliberately
Create a mapping between old and new account codes, customer records, supplier records and tracking categories. Decide how to handle obsolete codes and duplicate contacts. Keep the mapping document so future reviewers can understand the change.
Confirm the VAT scheme, return periods, tax codes and opening VAT position. An invoice already reported on a return must not become newly reportable simply because it was imported as unpaid. Cash accounting and outstanding receipts or payments require particular attention.
If you use Making Tax Digital for Income Tax, check the changeover against HMRC's step-by-step guidance. Agree which software will hold the records and send the relevant updates before disconnecting the previous arrangement.
An illustrative opening-balance error
Imagine a consultancy moving at 30 June. It imports a trial balance containing customer debts, then imports the same unpaid invoices using entries that also increase the debtors control account. The new system shows customer debts twice.
The migration reviewer compares the customer listing to the control account and spots the discrepancy. The team revises the import method so outstanding invoices and the opening ledger agree without duplicating balances. This is an illustrative example: the correct import process depends on the software and its opening-balance functions.
A similar problem can arise when a new bank feed downloads transactions already included in the import. Set the feed start date deliberately and test for overlaps.
Sign off before normal processing begins
Run a sample invoice, supplier bill, refund and payment match. Compare reports with the old system at the cut-off date. Test permissions, attachments and exports. Resolve each difference or document an approved explanation.
Keep a migration issues log and review the first month-end closely. Leave the old system available for an agreed period if necessary, with responsibility for any continuing cost clearly assigned.
Ask EPOS Accountancy about accounting software support. Supply your current system, proposed destination, cut-off date and trial balance. Agree extraction, reconciliation, import and review responsibilities before work starts, and use pricing to begin a scoped enquiry. Third-party integration work and specialist migrations require separate confirmation.