Data migration

What it means

Data migration is moving data from an old system to a new one, for example when changing accounting software, introducing an ERP, or switching CRM or payroll system. It covers deciding what to move, converting formats, the transfer itself and checking that nothing was lost or altered.

Not everything is moved. In accounting, opening account balances, open receivables and payables, fixed assets with their depreciation history and master data are typically transferred. Old transactions stay in the previous system or an archive, where they must remain accessible for the statutory period.

Migration is a risky project. Transfer errors do not show immediately but at year end, in payment reminders or at an audit. It is therefore planned with slack, a test transfer and a clear check of the result.

How it works in practice

We recommend switching accounting systems at the start of an accounting period. Opening balances are then taken from the balance sheet after opening the books, and there is no need to move part-year movements, which greatly reduces the risk of errors.

Before the transfer we clean the data: merging duplicate partners, closing old open items and checking balances. Afterwards we compare the balance sheet, sub-ledgers and fixed assets in the old and new systems. Every difference must be explained.

The old system or an export of it must be kept in readable form for the whole retention period. In an audit of earlier years the company must be able to produce its accounting records even if it no longer uses the original program.

What to watch out for

The most common mistake is migrating mid-year under deadline pressure without testing. The result is balance differences that take months to sort out and financial statements that are hard to assemble from two systems.

The second risk is losing access to old data by ending the old program’s licence. Before terminating the contract, have a complete export in an open format and check that the data can actually be read from it.