A till migration rarely fails because of the new till. It fails because the old one is switched off on migration day and three weeks later somebody asks where last year’s takings went.
The good news: there is an order in which nothing gets lost. The bad news: it does not start on migration day but roughly four weeks before.
1. What can actually be lost when you switch tills?
Four things, in descending order of how much trouble losing them causes:
The till records themselves
Every past transaction, including the signatures from the certified security module. German law requires them to be retained regardless of whether the till that produced them still exists.
The product data
Menu, prices, tax rates, product groups, mappings. Re-entering two hundred items by hand is a full day — and a day on which typos find their way into tax rates.
Customer and guest data
Regulars, balances, vouchers, open invoices. Vouchers are the quiet classic: they sit in guests’ wallets and resurface six months after the switch.
Open transactions
Unclosed tables, prepaid reservations, running invoices. None of them survive a migration, so they have to be closed beforehand.
2. Which tax office notification does almost everyone forget?
Electronic till systems have to be reported to the tax office — electronically through “Mein ELSTER” or the ERiC interface, not informally. The procedure has existed since 1 January 2025; tills acquired before 1 July 2025 had to be reported by 31 July 2025. This runs both ways: the new till has to be registered, the old one deregistered.
The deadline is one month and runs from acquisition or decommissioning (section 146a(4) of the German Fiscal Code), not from the moment somebody remembers. Notifications are made per business premises, and each one lists every till at those premises — including the ones that stay. Anything specific to your case, such as several premises, belongs with your tax adviser before the old till is dismantled.
3. What happens to the old security module?
The security module is not an accessory that goes in the bin with the old till. The records it signed must be retained and, in an audit or a spot check, be available in machine-readable form in the format the tax authority prescribes.
In practice that means one of two things: either you export the data completely in that format and keep the export, or you keep the module along with the ability to read it. The first is far less fragile — an export has no battery and needs no reader that may not exist in five years.
With cloud-based modules it depends on the contract: when it lapses, access often lapses with it. Read that clause before you cancel.
4. In what order does a till switch run?
Four weeks out
Request the export from the old till — records in the tax authority format, product data, customer data, outstanding vouchers. In writing, with a deadline. Some providers take their time, and some charge for it.
Three weeks out
Check the export, do not just file it. Spot check: can you find a day from last year? Are the tax rates mapped correctly? An export nobody has opened is not a backup.
Two weeks out
Move the product data into the new till and read it back. Especially: takeaway versus eat-in tax rates, deposits, discounts, vouchers.
The cut-over date
A month boundary, better a quarter, best of all the turn of the year. Switching mid-month means your accountant has to assemble one month from two systems.
The day before
Close every open transaction. End-of-day on the old till, printed and filed.
Afterwards
Do not dismantle the old till — leave it standing for two to three months, taking no payments but still readable. In our experience the questions arrive in week six.
5. What should your accountant know beforehand?
A short call before the switch saves the long email after it. What they want to hear: the date, which system is coming, what the export looks like and whether the chart of accounts changes. If your bookkeeping runs over an interface, they will also want to know whether it changes — and whether there is a gap between the old and the new export.
