What a time sheet for clients is
A time sheet (often written timesheet) is the list of your working time for one customer in a given period: on which day you worked how long on what, with the total at the end. You send it with the invoice or before it for approval. Folnaro calls it a time sheet too.
How to track, round and bill time in the first place is in the guide to time tracking for freelancers. This guide is about the document your customer holds in their hands.
When you need a time sheet
There is no general duty to send customers a time sheet. It is often in the contract, though: agencies, corporations and public bodies frequently ask for one with every invoice, sometimes in their own template or portal. Check the billing clauses of your contract.
Even without such a clause, the time sheet has a reason in tax law. A German invoice must state the scope and type of the service (§ 14 Abs. 4 Satz 1 Nr. 5 UStG). “Consulting” alone hardly does that. “24.5 hours of concept and implementation, website relaunch” is much better, and the time sheet supplies the details.
When the time sheet is part of the invoice
An invoice may consist of several documents. Together they must contain all mandatory details (§ 31 Abs. 1 UStDV). One of them, the invoice itself, states the net amount and the VAT each in total, and that document must name the others that contain the remaining details.
For you this means: if your invoice only says “development as per time sheet of 31 October 2026”, the time sheet becomes part of the invoice. It then has to be named clearly, by date, period or a number, and your customer has to have it, or they cannot follow the invoice. The simplest way is to send it with the invoice.
Retention follows from that. Since 2025 you keep invoices for eight years (§ 14b Abs. 1 UStG, § 147 Abs. 3 AO), together with every document that belongs to them. If your invoice refers to the time sheet, you file it as well and do not change it afterwards. More in the guide to retention periods.
If the invoice already describes the service fully by itself and the time sheet is just information for your customer, it is not part of the invoice. Keeping it is still worthwhile in case someone asks later.
What a good time sheet contains
- Header: your name, the customer, the project and the period, for example “1 to 31 October 2026”.
- Per entry: date, duration and a description your customer understands. Start and end times are only needed if your contract asks for them.
- Activity: if you separate concept, implementation and coordination, subtotals per activity help.
- Rounding: if you bill in quarter hours, the time sheet shows the same rounded values as the invoice.
- Total: the hours of the period and, if you like, rate and amount.
- Allowance: if your customer pays for a fixed allowance of hours, separate the included hours from the extra billable ones.
- Approval: if needed, a line for your customer’s name, date and signature.
A simple template
| Date | Activity | Description | Hours |
|---|---|---|---|
| 10/06/2026 | Concept | Workshop on the site structure with the marketing team | 3.0 |
| 10/08/2026 | Implementation | Built home page and navigation | 5.5 |
| 10/09/2026 | Coordination | Feedback round, changes to the navigation | 1.25 |
| Total October | 9.75 |
Approval by the customer
Many customers want to check the hours before the invoice arrives. That works in your favor: an approved time sheet makes later arguments about single entries rare.
Agree in the quote or contract on how approval works. Common options are a signature on the PDF, a short confirmation by email, or a deadline after which the hours count as approved. Send the time sheet shortly before the end of the month, so there is time for questions and the invoice still goes out on time. Keep the approval together with the time sheet.
Common mistakes
- Totals that differ. If the time sheet shows 12 hours and the invoice 12.5, your customer will ask. Work out both from the same entries with the same rounding.
- Vague descriptions. “Misc” or “support” without content invites cuts. Half a sentence per entry is usually enough.
- Changes afterwards. Once the invoice has gone out and refers to the time sheet, you change neither. A mistake is fixed with an invoice correction.
- Internal time. Non-billable time does not belong on the time sheet, unless you deliberately want to show it as free of charge.
This guide explains the rules in general and is not tax advice.
Common questions
Do I have to send my customer a time sheet?
Not by law, as long as your invoice describes the scope and type of the service well enough by itself. Many contracts ask for one, though. Even without a duty it answers questions before they come up.
Does the customer have to sign the time sheet?
Only if you agreed on it. A signature or a confirmation by email is good evidence that the hours were agreed. It is not a condition for the invoice to be valid.
May I change the time sheet after sending it?
Not if it is part of the invoice: then the same applies as to the invoice itself. If you spot a mistake, you correct the invoice and send a new time sheet with it.
How long do I keep time sheets?
If the time sheet belongs to the invoice, eight years like the invoice, counted from the end of the year in which the invoice was issued. If it is only information for your customer, it counts as another record as far as it matters for taxation, and for those the period is six years (§ 147 Abs. 1 Nr. 5 and Abs. 3 AO). If in doubt, keep it as long as the invoice.