Migrate localization from one ERP to another without losing compliance
When a group replaces its ERP, the localization is the part most likely to be underestimated. The old system has years of country settings, numbering sequences, tax codes, e-invoicing connections and history that the authority may still ask for. The new one has to take over every obligation on a fixed date without a gap, and the open items you carry over have to agree with the old books to the cent.
Part 3 of 3 in the series Sizing and moving. Read this first: Localization for a small subsidiary: a decision tree and the minimum obligation list.
This guide gives a migration checklist, a way to compare the two ERPs using the evidence on this site, and a worked tie-out of open items through a migration clearing account.
Compare support before you plan
For each country, open the country page and compare the two products column by column:
- the e-invoicing matrix (
/<country>/#e-invoicing): support type and whether the evidence is verified; - the VAT reporting and SAF-T rows: which ERP documents support for each return and audit file;
- the ERP pages under ERPs, which list the guides and the evidence for each product.
Record the result in a simple table. Anything where the old ERP has documented support and the new one has none, or only unverified evidence, is a migration risk to resolve first. Use verify ERP localization support to collect the evidence, and estimate localization effort to size it.
| Obligation | Old ERP | New ERP | Gap | Action |
|---|---|---|---|---|
| E-invoicing, outbound | verified, native | unverified | Yes | Confirm with documentation before design |
| VAT return | documented | documented | No | Re-map boxes and test |
| Audit file | documented | evidence not established | Yes | Confirm, or plan an alternative export |
Migration checklist
Before cutover
- Choose the cutover date. A period start, ideally a VAT period start and a fiscal year start, keeps returns simple.
- Decide what history moves: open items only, balances by period, or full transaction history. Decide where the rest is kept and how it can be read and exported later.
- Rebuild tax codes and the tax-code-to-box matrix in the new ERP; see map tax codes to VAT return boxes.
- Rebuild the chart-of-accounts mapping and numbering; record the last number used in the old system and the first in the new one.
- Register the new system with any e-invoicing network, provider or authority portal; plan certificate and endpoint changes so that inbound documents are not lost.
- Test the first return and the first audit file from the new system on migrated test data.
At cutover
- Close the old system for posting.
- Extract the trial balance and open items at the cutover date.
- Load open items and balances through a migration clearing account.
- Prove the tie-out (below). The clearing account must end at zero.
After cutover
- File the last return from the old system and the first from the new; make sure no period is filed twice or missed.
- Keep the old system's data readable and exportable for as long as the retention rules require. An auditor may ask for an audit file for a period that only the old system holds; see respond to a tax audit data request.
See ERP cutover and tax history for the tax-history side in more detail.
Worked example: open items through a clearing account
The amounts are illustrative round numbers. At the cutover date, the old ledger shows:
| Account | Debit | Credit |
|---|---|---|
| Trade receivables (3 open invoices) | 5,000 | |
| Bank | 4,000 | |
| Trade payables (2 open invoices) | 2,000 | |
| Equity and reserves | 7,000 | |
| Total | 9,000 | 9,000 |
The open items are loaded one by one so the new ERP knows each invoice, its due date and its tax details. The other balances are loaded as a journal. Everything passes through a migration clearing account.
| Step | Account | Debit | Credit | Note |
|---|---|---|---|---|
| Load open customer invoices | Trade receivables | 5,000.00 | 3 invoices | |
| Migration clearing | 5,000.00 | |||
| Load open supplier invoices | Migration clearing | 2,000.00 | ||
| Trade payables | 2,000.00 | 2 invoices | ||
| Load the remaining balances | Bank | 4,000.00 | ||
| Migration clearing | 3,000.00 | |||
| Equity and reserves | 7,000.00 |
After the three loads, the clearing account is 5,000 credit less 2,000 and 3,000 debit, which is zero. The new trial balance equals the old one. Then check the detail: the three receivables in the new subledger have the same numbers, dates, amounts and VAT as in the old one, and their total is 5,000. If the clearing account does not end at zero, an open item is missing, duplicated or loaded with the wrong amount. Find it before you post anything else.
Worksheet
Use the ERP migration localization checklist and tie-out.
Worksheet: ERP migration localization checklist and tie-out
Copy this worksheet for each case. It records decisions and evidence; it does not determine the tax or legal treatment.
Show the worksheet
Use with the ERP migration guide.
Support comparison
| Country | Obligation | Old ERP evidence | New ERP evidence | Gap | Action and owner |
|---|
Before cutover
- ☐ Cutover date chosen (period start, ideally VAT and fiscal year start)
- ☐ History decision: what moves, where the rest stays, how it is exported later
- ☐ Tax codes and box matrix rebuilt and tested
- ☐ Chart-of-accounts mapping and numbering rebuilt; last old and first new numbers recorded
- ☐ E-invoicing, portal and bank registrations moved; certificates and endpoints planned
- ☐ First return and audit file tested on migrated data
Tie-out at cutover
| Account | Old ledger | Loaded in new ERP | Difference |
|---|---|---|---|
| Receivables (subledger total) | |||
| Payables (subledger total) | |||
| Other balances | |||
| Migration clearing | — | must be 0 |
After cutover
- ☐ Last return from old system filed; first from new system filed; no period missed or doubled
- ☐ Old data readable and exportable for the retention period
Sources checked: 27 October 2026. Support comparisons use this site's matrix and reporting data; each cell links to its evidence. No vendor capabilities are stated in this guide.
Related guides and data
Part 3 of 3 in the series Sizing and moving. Read this first: Localization for a small subsidiary: a decision tree and the minimum obligation list.
- How to replace an ERP without losing tax-reporting history
- How to verify an ERP localization before signing a contract
- Estimate localization effort per country and ERP from the evidence
- Chart of accounts, statutory journals and document numbering for a new country
Data on this site: E-invoicing country × ERP matrix · VAT reporting requirements by country · SAF-T and audit files by country · ERP profiles and country support
In Planning and rollout: previous Localization governance: a RACI per obligation type and a review calendar · next Localization for a small subsidiary: a decision tree and the minimum obligation list · Guides by task · All guides
Vendor documentation is cited only as an example of the level of evidence to ask for; it is not a recommendation or a ranking. This guide is general information, not tax or legal advice. Checked 2026-10-27.
Related: Glossary – abbreviations and terms used in these guides (SAF-T, Peppol, CTC, EN 16931, IFRS and more).
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