Keeping a cash book (Kassenbuch) in Germany: who must, what goes in and how to do it right

Who has to keep a cash book?

The answer depends on how you determine your profit – and whether the business has a till at all. A cash book is the record of the cash balance of a business till: opening balance, every receipt, every expense, closing balance.

Companies that prepare balance sheets are obliged to keep double-entry books under commercial law (§ 238 HGB) and § 140 or § 141 AO. If such a company holds cash, a cash account with a cash book is mandatory. For the self-employed using the cash-basis profit statement (EÜR), on the other hand, no rule explicitly requires a cash book. Nevertheless the recording obligations apply: cash receipts and expenses must be recorded individually, completely, correctly and daily (§ 146 Abs. 1 AO), plus the records for VAT (§ 22 UStG).

No till? Then you do not need a cash book either

Many freelancers – developers, translators, consultants – receive their money exclusively by bank transfer. If they occasionally pay for a parking ticket or office supplies in cash, they are putting money in from their private assets. This receipt is booked as a business expense, with the counter-entry as a private contribution (Privateinlage, SKR03 account 1890). No business till with its own balance is created – and therefore no cash book obligation and no risk of a negative cash balance.

A till only makes sense when you regularly take in cash or deliberately hold a cash balance in the business, for example for change.

What goes into a cash book?

Each line describes a single transaction. These details are customary and meet the requirements of the GoBD:

• Sequential number and date of the transaction.
• Receipt number – every line has a voucher (till receipt, receipt, self-made receipt, deposit slip).
• Description: what, from whom or to whom.
• Receipt or expense in euros, separated by tax rate (19 %, 7 %, tax-exempt).
• Balance after the transaction or at the end of the day.
• Cash movements between till and bank (cash in transit) and private withdrawals and contributions.
• Cash movements in chronological order – no lump entry “October income”, except for the daily cash report of an open till.

Ready for a cash count: book balance equals actual balance

Kassensturzfähig (ready for a cash count) means: the balance according to the cash book must match the counted cash at all times. An auditor can count the till and compare it with the cash book. You must be able to explain differences; regular, unexplained deviations indicate missing records.

A negative cash balance is impossible – you cannot take more out of a till than is in it. If one appears, receipts or contributions are missing, or expenses were wrongly booked from the till instead of privately. The tax office may then make an estimate. So count the cash at every cash closing and record the result in a counting log (Zählprotokoll).

Example: one week of the cash book

Marco gives freelance photography courses and sells photo prints at events (19 % VAT). He keeps a till with change. This is what his week looks like:

How to read the example correctly

The €238.00 income from the photo prints contains €200.00 net and €38.00 VAT, the course fee of €178.50 contains €150.00 net and €28.50 VAT. Both amounts belong in the VAT return (Umsatzsteuer-Voranmeldung) for the period. From the office supplies for €23.80 Marco can claim €3.80 input VAT; the stamps are VAT-exempt, so there is no input VAT.

The deposit of €400.00 into the bank is neither income nor an expense for tax purposes, but only cash in transit (Geldtransit): the money moves from the till to the bank account. On Friday evening Marco counts €123.70 in the till – book and actual balances match, the till is ready for a cash count. If he had forgotten to book the deposit, the cash book would show a balance of €523.70, but only €123.70 would be in the till – a difference an auditor sees immediately.

Electronic register with TSE or open till?

If you record your cash receipts with an electronic recording system – cash register, PC or tablet POS – you must use a certified technical security device (technische Sicherheitseinrichtung, TSE) under § 146a AO and the Cash Register Security Ordinance (Kassensicherungsverordnung, KassenSichV). A receipt must be created for every transaction and offered to the customer (Belegausgabepflicht); an electronic receipt is also allowed. An exemption is only possible on application when selling goods to many unknown persons.

Since 2025 you must notify the tax office of every electronic recording system via ELSTER, within one month of purchase or decommissioning. Breaches of the TSE obligation can be punished with a fine of up to €25,000 (§ 379 AO). An electronic register is not mandatory: the open till (offene Ladenkasse), i.e. a cash box without electronic recording, is still allowed. You then keep a daily cash report and count the balance daily.

When selling goods for cash to many unknown persons, § 146 Abs. 1 AO allows you to dispense with recording each sale individually – but only without an electronic register system. You then determine the daily takings backwards (retrograde) using a cash report:

• Counted closing cash balance of the day (counting log with denominations).
• minus opening cash balance (= previous day’s closing balance).
• plus expenses paid from the till, with receipts.
• plus private withdrawals and deposits into the bank.
• minus private contributions.
• = daily takings, separated by tax rate; keep the counting log and the expense receipts with the cash report.

Cash inspection: an unannounced visit

Since 2018 the tax office may carry out a cash inspection (Kassennachschau) under § 146b AO during business hours without prior notice. The official may first make test purchases incognito, then identify themselves and request: the cash book, cash reports and counting logs, access to the register data via the digital interface, the process documentation and, if necessary, a cash count. If doubts arise, they can move on to a tax audit (Außenprüfung) without a prior audit order.

So keep the cash book, the receipts of the last few days and the documents on the register system to hand, even if you are not there yourself – employees should know where everything is and who in the business may give information. A cash inspection is not a tax audit, but it can turn into one.

Common cash book mistakes

These mistakes regularly lead to estimates in audits:

• Cash book in an editable spreadsheet without a log – later changes cannot be detected.
• Entries made afterwards for the whole month instead of daily.
• Negative cash balance because cash deposits into the bank or private contributions are missing.
• Card payments recorded in the cash book – they belong on the bank account, not in the cash till.
• Private expenses from the business till without being booked as a private withdrawal.
• Corrections with correction fluid or overwriting in a paper cash book.
• Entertainment receipts without occasion and participants (documenting entertainment expenses correctly).

Cash book with Kontelio

Kontelio is not a cash register system and has no TSE; for sales at the counter you need a certified register system or an open till. For your bookkeeping you set up a cash account in Kontelio (from the Business plan) under Bank and cash. You record cash expenses and cash receipts with a voucher, and deposits into the business bank account as cash in transit. The cash book shows all movements in chronological order with the balance after each day, can be exported as CSV or PDF and rejects a cash payment that would take the balance below zero. Bookings follow SKR03, and everything flows into the Anlage EÜR. You file receipts in the receipt management.

Frequently asked questions