E-Rechnung for IT Freelancers in Germany: What You Must Do Before 2027 and 2028

If you are an IT freelancer in Germany and your Gesamtumsatz (total net turnover) in 2026 stays at or below €800,000, the law lets you keep sending PDF invoices, with the client's consent, for work done in 2027. From 1 January 2028, invoices to German business clients must be structured e-invoices, apart from a few small exceptions. Receiving e-invoices has been mandatory since January 2025. Watch December 2026: on the wording of the law, work from that month invoiced in January 2027 already needs an e-invoice. The deadline that will catch most contractors is not the law, though. It is the client's accounts-payable department and the agency's self-billing system, and both are likely to move during 2027.

When do IT freelancers have to send e-invoices?

The obligation is phased by the date of the work and by the size of the business that issues the invoice. Receiving is already mandatory for every German business. For issuing, PDF and paper remain allowed for supplies in 2025 and 2026, for supplies in 2027 only if the issuer's previous-year turnover was €800,000 or less, and not at all from 2028.

To put the threshold in proportion: a contractor billing €95 an hour for 1,700 billable hours ends the year at €161,500 net. One-person IT businesses sit far below €800,000, so their legal switch date is 1 January 2028. That date is the latest you can move. In practice you will probably have to move earlier, for the reasons in the next sections.

Why your December 2026 invoice is the first real deadline

Each transition rule has two dates: the period in which the work was done, and the last day the PDF may be sent. For work in 2025 and 2026, the PDF must go out by 31 December 2026. The 2027 relief covers only work performed in 2027. Read together, the wording of §27 Abs. 38 leaves no PDF route for December 2026 work invoiced in January 2027.

Most contractors bill monthly in arrears, and agencies self-bill after the timesheet is approved. December's hours are typically approved and invoiced in early January. On the wording of the law, that invoice has to be an e-invoice, even if you are far below €800,000, unless it goes out before 31 December. The same pattern repeats a year later: December 2027 work invoiced in January 2028 needs an e-invoice regardless of size.

You have two clean options for the December invoice: send it on 31 December at the latest, or send it as an e-invoice. Raise it with your agency now, because their year-end run decides it for you. An invoice may be issued up to six months after the work (§14 Abs. 2 UStG), but that deadline does not move the transition dates. An EDI connection agreed with a client stays allowed until the end of 2027 regardless of size, which matters only if a large client already runs one.

Does the e-invoice rule apply to my contract at all?

The mandate covers domestic B2B supplies only. Both you and your client must be established in Germany, through a registered seat, management, a permanent establishment involved in the supply, or failing those, residence. Invoices to private customers and cross-border invoices stay outside the mandate, and so do a few small exceptions.

Three questions settle it:

1. Is the client a business buying for its business? If it is a private person, no e-invoice duty.
2. Is the client established in Germany? A Swiss, Austrian or Dutch end client billed directly is outside the German mandate, and your reverse-charge invoice continues as before.
3. Are you established in Germany? If you bill from a company established outside Germany, you are outside this domestic mandate as well.

Three yeses mean you are in scope. The exemptions rarely apply to contractors. A Kleinunternehmer (small business under §19 UStG) may always send a sonstige Rechnung, the legal term for any invoice that is not an e-invoice, under §34a UStDV, and invoices up to €250 gross may too (§33 UStDV). A contractor's monthly invoice exceeds both limits, so neither will help you.

Fixed monthly retainers deserve a note. If a contract was invoiced once by a Dauerrechnung (a standing invoice covering recurring payments) before 1 January 2027, you do not have to issue an additional e-invoice while nothing changes. A new rate, a new scope or a new contract triggers the e-invoice.

Agency self-billing: the Gutschrift is now your invoice

Most agency contracts in German IT contracting run on the Gutschriftverfahren (self-billing): the agency writes the invoice from your approved timesheet, and you never send one. A Gutschrift is an invoice in law, so the e-invoice rules cover it too. Your job changes from writing invoices to checking the XML you receive.

The practical consequence is easy to miss. The agency's system will soon send you a hybrid file or a bare XML, and the XML is the legal invoice, not the PDF view. If the two differ, the PDF can count as a second sonstige Rechnung, and two invoices for one supply can make the VAT owed twice. So the check runs on the data: hours, rate, service period, VAT rate and amount, your tax number, and the word Gutschrift, which §14 Abs. 4 Nr. 10 UStG requires on every self-billed invoice.

You keep one strong right. Under §14 Abs. 2 UStG a Gutschrift loses its effect as an invoice as soon as you object to it. Use that when the XML is wrong, in writing, and ask for a corrected e-invoice that references the original.

One point is unresolved. §27 Abs. 38 ties the 2027 relief to the turnover of the business that issues the invoice, and in self-billing the agency issues it. Whose turnover counts is not settled in the sources I checked. Large agencies are far above €800,000 either way, so expect e-Gutschriften from them during 2027 and ask your Steuerberater (tax adviser) how your own books should treat them.

The timesheet trap in T&M invoices

Time-and-material invoices usually read "service as per Stundennachweis" (timesheet) with the sheet attached. According to the BMF's guidance, as summarised by Sage from the updated FAQ of March 2026, documents that accompany an invoice must be embedded in the e-invoice file. A reference to an external attachment no longer works.

This hits contractors harder than anyone, because the timesheet often carries the one mandatory item the invoice itself skips: the extent of the service. There are two clean ways out:

• Put the substance in the invoice lines. One line per month or per project phase, quantity in hours (or days), unit price equal to your rate, and the service period set on the line or the invoice. Then the XML carries everything §14 Abs. 4 asks for, and the timesheet becomes supporting evidence rather than part of the invoice.
• Embed the timesheet in the file. XRechnung and ZUGFeRD both allow attachments inside the invoice. Do this when the client insists that the signed sheet travels with the invoice.

The approach to avoid: a minimal XML with one lump sum, the details in a separate PDF timesheet in the same e-mail. If the extent of the service lives only outside the invoice, you have created a content problem that the client's system may reject.

What must the XML of a contractor invoice contain?

The mandatory content of an invoice did not change with the e-invoice. §14 Abs. 4 UStG still lists it. What changed is where it must sit: in the structured data, where the client's software reads it, not only in a PDF view. For a typical T&M contractor invoice, that means:

Add what the client's accounts payable needs to route the invoice, mainly the purchase-order or contract number. That is not a tax requirement, but an invoice without it is the one that sits in a queue.

XRechnung or ZUGFeRD: which format should a freelancer use?

Both are legal e-invoices if they follow the European standard EN 16931. XRechnung is pure XML. ZUGFeRD 2.x is a PDF with the XML embedded. For private-sector clients, ZUGFeRD in the EN 16931 profile is the practical default, because one file serves the human reader and the accounting system.

Use XRechnung when a client asks for it. If you have ever billed a federal authority, you already know it and its Leitweg-ID routing number. Never use the ZUGFeRD profiles MINIMUM or BASIC-WL: they lack invoice lines and do not count as e-invoices. And generate the PDF and the XML from the same data in one step, so they cannot differ.

What goes wrong: format errors, business-rule errors, content errors

The administration distinguishes three types of error, and they carry different weight for your client's input-VAT deduction. A format error means the file is not an e-invoice at all. A content error means a mandatory item is wrong or missing. A business-rule error means the file is technically valid but mandatory fields are missing or values contradict each other; it only matters if it touches a mandatory VAT item.

Format and content errors directly endanger the client's input-VAT deduction. Once the e-invoice duty applies, in principle only an invoice in the required format entitles the client to deduct input VAT, and accepting a PDF despite the duty can cost them the deduction. That is why accounts payable is likely to bounce a broken file instead of paying it, and your payment slips.

Validate before you send. The public administration publishes a free validator (the KoSIT validator), and many invoicing tools can check a file on export. If an invoice went out wrong, correct it with a new e-invoice that clearly references the original. Under certain conditions that correction works retroactively.

What if the client still wants a PDF?

Until the transition ends, both sides may agree on a PDF, and many clients will ask for exactly that because their own process is not ready. That is legal for your 2026 work, and for your 2027 work if you stayed below the threshold. Get the consent in writing, an e-mail is enough, and keep it with the invoices.

The reverse case will be more common during 2027: you are allowed to send a PDF, but the client will not accept one. A large client cannot see your previous-year turnover, and its input-VAT deduction depends on getting the right format whenever an e-invoice is required. The simplest internal rule for them is "e-invoice from every German supplier". That is my expectation from the field, not a legal requirement, but plan for it. Arguing a legal exemption with an accounts-payable team is a fight a freelancer does not win quickly.

Receiving and archiving: what you must do already today

Since 1 January 2025 you must be able to receive e-invoices, and an e-mail inbox is enough. Your own suppliers will send them: software subscriptions, hardware, coworking, the agency's Gutschrift. What you do with the file afterwards is what the tax office checks.

Keep invoices for eight years, counted from the end of the year the invoice was issued (§14b UStG). For an e-invoice, the original is the XML. Store it unchanged and machine-readable, not only as a printed or rendered PDF. Keeping the validation report next to the incoming invoice is recommended: it shows the file was compliant when it arrived.

A folder structure is enough for a one-person business, as long as it keeps the XML untouched and you can find an invoice by number and date eight years later. If your bookkeeping software or your Steuerberater's system imports the XML, even better, because that also removes the typing.

A plan for a one-person IT business, October 2026 to January 2028

The switch is small for a single contractor: a tool that exports the right format, a clean set of invoice lines, and a filing habit. What takes time is getting each client and agency to confirm what they will accept. Start that conversation this quarter.

1. Now, Q4 2026: check your contracts. List every client and agency, note who self-bills (Gutschriftverfahren) and who expects your invoice, and look at the framework agreement for any clause on invoice format or delivery channel.
2. By December 2026: settle the December invoice. Either the December 2026 invoice goes out by 31 December, or it goes out as an e-invoice. Agree which with each agency now.
3. Now: make sure you can receive. Read the XML of the e-invoices that already reach you, and start filing the XML files themselves.
4. By January 2027: pick a tool that exports ZUGFeRD in the EN 16931 profile and XRechnung, supports line-level service periods, and can embed attachments.
5. January 2027: send your first e-invoice to each direct client and ask accounts payable whether it was processed without a manual step. Fix what they report while the PDF is still allowed as a fallback.
6. During 2027: check every agency e-Gutschrift against your timesheet in the XML, and object in writing when it is wrong.
7. By the end of 2027: e-invoices only, for every German business client. From work performed on 1 January 2028 the PDF is gone for good.

Check the details of your own setup, above all the self-billing question, with your Steuerberater. The e-invoice itself is a small technical step. The work is in agreeing with each client on what the invoice must contain, and that needs to start now.

Related field notes:

• How to become an IT freelancer in Germany
• IT freelancer rates in 2026 and the experience premium
• AI discounts in time-and-material contracts
• NIS2 supplier clauses for freelance contractors
• Statusfeststellung reform
• Freelancer-Kompass 2026: why projects stall on the client side