If you earn money on the side as a freelancer, private tutor or online seller, you eventually have to report that income in your tax return. For many small activities, the income surplus calculation (Einnahmen-Überschuss-Rechnung, EÜR) is the right tool, because it only asks what came in during the year and what went out. That sounds simple, but the payment date, the records and a clean separation from private transactions decide whether the result holds up.
Kurz beantwortet: The EÜR is a simplified way of determining profit under section 4 subsection 3 of the Income Tax Act (EStG). Business income counts in the year it is received, and expenses in the year they are paid. It is filed electronically through ELSTER together with the Anlage EÜR. According to the IHK Köln, records should be kept for eight years. Last updated: November 2026.
The most important points in brief
- The EÜR follows the principle of inflow and outflow, so the date of payment counts, not the invoice date.
- Regularly recurring payments such as rent or interest can fall into the previous or the following year under a ten-day rule.
- Loans do not count as income, and repayments of loans do not count as expenses.
- The Anlage EÜR is generally transmitted electronically through ELSTER. Receipts are not sent to the tax office.
- According to the IHK Köln, accounting vouchers must be kept for eight years and business letters for six years.
What is the EÜR and when does it suit a side job?
The income surplus calculation is a method of determining profit. It sets business income against business expenses, and the difference is the profit. For side jobs, freelance work and small trades, it is often the obvious method, because it does not require double-entry bookkeeping.
Whether you may use the EÜR depends on turnover and profit, and on whether other laws impose a duty to keep books. These thresholds are adjusted from time to time, so check the current position before you commit to this method for the long term. Older IHK leaflets name thresholds that no longer apply, so rely on the current rules.
When does a payment count as income?
The decisive point is when the money is received. An invoice issued in December but paid in January belongs to the following year. The same logic applies to expenses: a bill you pay in December can be deducted in the current year, even if the invoice arrives in January.
There is an exception for regularly recurring payments. If a payment falls within ten days before or after the turn of the year, it is assigned to the year to which it economically belongs. This concerns, for example, a monthly rent or interest, but not every payment made at year end.
| Transaction | Effect on the EÜR | Note |
|---|---|---|
| Fee paid in December | Income of the current year | The receipt of money is decisive |
| Fee paid in January for work done in December | Income of the following year | The inflow decides, not the service |
| Loan taken out | No income | The money has to be repaid |
| Repayment of a loan | No expense | Interest, however, can be an expense |
Which expenses can you deduct?
Business expenses are costs connected with your activity. Depending on the work, they include software, specialist literature, work materials or travel costs. Whether an expense is business or private in nature must be assessed case by case. A clear separation helps to avoid disputes with the tax office.
Also check the year in which the expense is recorded. A specialist book bought and paid for in December counts in the current year, even if the invoice arrives in January. For ongoing business expenses, you deduct at the point of payment, not at the point of purchase. Larger purchases such as a laptop are generally depreciated over their useful life, and separate rules apply that you should clarify beforehand.
How do you file the EÜR?
The Anlage EÜR belongs to your income tax return. According to the IHK Bonn document (dated October 2018), it must generally be transmitted as an official electronic data set through ELSTER. The official paper form is allowed only on application, to avoid unreasonable hardship. The tax office receives the income tax return with its attachments and the EÜR, but no receipts.
- Sort all income and expenses of the year by payment date.
- Keep a list with date, amount, type and receipt, ideally updated during the year.
- Complete the Anlage EÜR through ELSTER and check the figures against your list.
- Store the receipts in an orderly, traceable way without sending them to the tax office.
How long must you keep receipts?
On its page about the retention of business documents, the IHK Köln names a period of eight years for accounting vouchers. According to that page, the period has applied since 1 January 2025, and previously it was ten years. For business letters, the page names six years. It cites section 147 subsection 1 of the Fiscal Code (AO) for the list of documents and section 257 of the Commercial Code (HGB) for the commercial duty.
Confirm with your tax adviser or the tax office which period applies to your EÜR. Plan the retention so that you can find receipts years later. A digital folder with a year structure is usually sufficient for this purpose.
Worked example for a side job
Assumption: in 2026 you work as a tutor and receive fees of 2,400 euros. Of this, 300 euros arrive in December, and a fee of 200 euros is paid only in January. You pay 120 euros for learning materials and 80 euros for travel that is business related. For the 2026 income, the amounts that actually arrived in 2026 count, and for expenses the amounts actually paid. The difference is the surplus that goes into the Anlage EÜR.
This example only illustrates the mechanism. It shows that the receipt of money decides and not the service, and that private transactions must be kept out of the calculation.
Typical mistakes with side jobs
The most common mistake is a mixed account without order. If private and business payments are constantly combined, every later allocation becomes laborious. A second mistake is missing receipts. Anyone who does not keep a receipt loses an expense he could otherwise deduct.
If you are unsure whether your side job already counts as self-employment, you can read the German guide on the EÜR for side jobs for additional notes. The article Nebenjob und Selbstständigkeit parallel also helps with classification.
Frequently asked questions
Do I have to use the EÜR for every side job?
Not every side job leads to an EÜR. A simple employment with wage tax deduction does not lead to it. The EÜR concerns income from self-employed or commercial activity. Check which type of income applies to your work.
Is a simple spreadsheet enough?
A clear list with date, amount, type and receipt is generally sufficient for the EÜR, as long as it is complete and traceable. What matters is that you transfer the figures from the list correctly into the Anlage EÜR.
Do I have to send receipts to the tax office?
No. The tax office receives the income tax return with the attachments and the EÜR, but no receipts. You must keep them, however, so that you can prove the figures if the tax office asks.
When does a payment in December still count in the old year?
If you receive money in December, it counts in the current year. For regularly recurring payments the ten-day rule applies, which can affect the previous or the following year depending on the situation. Note individual transactions precisely.
What if I find an error in the EÜR?
Correct the error promptly and, where necessary, clarify with the tax office or a tax adviser how it should be treated. Note what you changed and why, so that the correction remains traceable later.
What to do now
- Start a running list of income and expenses at the beginning of the year.
- Collect all receipts digitally and assign each one to its payment date.
- Check in December and January which payments belong to the current year and which to the following year.
- Transfer the totals into the Anlage EÜR through ELSTER and keep the receipts for the required period.
Related reading
- Gründung neben dem Studium: Förderprogramme und Beratung im Überblick
- Kleinunternehmerregelung 2025
- Nebenjob und Selbstständigkeit parallel
- Steuererklärung für Studenten (in German)
Sources: IHK Bonn: Profit determination by income surplus calculation (in German, document dated October 2018), IHK Köln: Retention of business documents (in German, page dated October 2026). The 2018 IHK leaflet serves here only for the basic principles of the EÜR. Check the decisive rules (section 4 subsection 3 and section 11 EStG) and the current transmission requirements in the law and with your tax office.
Last updated: November 2026. This guide is general information, not individual advice.
