Germany's e-invoicing mandate from 1 January 2027: how installation companies should prepare their billing

In February 2027, the billing clerk at an installation company writes the January invoice for a network operator. She checks the meter swaps reported from the field against the purchase order and, as usual, emails a PDF with the unit list and photos.

If the company's total turnover in 2026 was above €800,000, that PDF is, as a rule, no longer enough. Work for other businesses in Germany must then be billed with an e-invoice. Taken literally, the law can also catch smaller companies if they don't invoice their December 2026 work until January 2027.

This post explains the rules (as of October 2026) and what they mean when you bill per unit. Then it turns to acceptance of the work (Abnahme), and why it matters particularly when a client looks shaky.

What applies from 1 January 2027

Under § 14 of Germany's VAT Act (Umsatzsteuergesetz, UStG), an e-invoice is an invoice in a structured format that can be processed electronically. As a rule, it follows the European standard EN 16931; examples are XRechnung and ZUGFeRD version 2.0.1 or later. The ZUGFeRD profiles MINIMUM and BASIC-WL do not qualify, and a plain PDF is not an e-invoice, even by email. Since 1 January 2025, every business in Germany must be able to receive e-invoices; according to the Federal Ministry of Finance (Bundesfinanzministerium, BMF), an email inbox is enough.

When it comes to issuing invoices, § 27(38) UStG sets transition rules:

Work from 2025 and 2026 may be invoiced until 31 December 2026 on paper or, with the recipient's consent, for example as a PDF.
Work from 2027 can still be invoiced that way until 31 December 2027, but only if the issuer's total turnover in the previous year was €800,000 or less.
EDI systems that do not meet EN 16931 remain allowed until 31 December 2027 if the recipient agrees.
From 1 January 2028, the obligation applies in principle to all domestic B2B business.

On 22 June 2026, the German Confederation of Skilled Crafts (Zentralverband des Deutschen Handwerks, ZDH) called for a delay to 2028. We are not aware of a draft law to that effect; § 27(38) UStG is unchanged (as of 21 October 2026). We would treat 1 January 2027 as a fixed date.

Does the obligation apply to your company?

For 2027, what counts is your total turnover (Gesamtumsatz) for 2026 as defined in § 19(2) UStG. It is calculated net and on the basis of payments received, so it is not the revenue figure in your annual accounts. If yours is just below the threshold, we would switch anyway. You won't know the final figure until the new year, because it also depends on what large clients actually pay by 31 December 2026.

Exceptions include small invoices of up to €250 including VAT, and work for private customers. In the BMF's view, though, the obligation also applies to invoices you send to housing companies, even those with only VAT-exempt rental income. And it covers reverse-charge invoices under § 13b UStG, where the client owes the VAT, as well as self-billing invoices (Gutschriften), where the client issues the invoice for your work.

Where a general contractor or network operator issues self-billing invoices for your work, its total turnover counts, not yours. If that turnover was above €800,000 in 2026, its self-billing invoices for work from 2027 onward must be e-invoices. Check each one against your unit list, and agree in advance how corrections work. An objection from you means the self-billing invoice no longer counts as an invoice, and the billing has to be redone.

Watch out for work done in December 2026

Read literally, § 27(38) no. 1 UStG allows a PDF or paper invoice for 2026 work only if the invoice is issued and sent by 31 December 2026. The BMF takes the same view in its guidance letter (BMF-Schreiben) of 15 October 2024, para. 63. The €800,000 rule only covers work from 2027 onward. On this reading, December work invoiced in January 2027 needs an e-invoice, even if your total turnover is €800,000 or less.

In our view, there are two clean options. One is to bring the December billing cutoff forward and send invoices for all finished work by 31 December 2026. The other is to use e-invoices for everything you bill from January 2027, including the last December jobs. Have your tax advisor confirm this reading, and the date of supply (when each job counts as performed for VAT purposes).

What the BMF added on 15 October 2026

The BMF letter of 15 October 2026 supplements the letters of 2024 and 2025 and changes no statutory dates. What matters for installation companies:

Description of the work: The structured part, meaning the machine-readable data, must describe the work unambiguously, stating what type of work it was and how much of it. It must also say what the work consisted of and, where relevant, where it was done. More detailed breakdowns can go in an embedded attachment.
Construction work: Until further notice, the BMF accepts a structured part that lists only the trades and their totals, provided a human-readable attachment based on the bill of quantities (Leistungsverzeichnis) is embedded and the structured part clearly refers to it. Whether meter swaps or fiber house connections count as construction work (Bauleistungen) in this sense is a question for your tax advisor.
Interim invoices (Abschlagsrechnungen) issued before your own e-invoicing obligation starts do not have to be e-invoices.
Consequences: Sending a PDF where an e-invoice is required is not an administrative offense under § 26a(2) no. 1 UStG. But the PDF is not a proper invoice either: in the BMF's view, your client in principle cannot claim input VAT on it. A later e-invoice can correct this retroactively (BMF letter of 15 October 2024, paras. 55 to 57).

What clients typically expect when you bill per unit

Network operators and general contractors often have their own invoicing rules. So do many metering point operators and housing companies. Typically, they ask for the purchase order number, often with the order line, and a contract or project reference. They usually also want the service period, plus the quantity and unit of measure on each line. One example is Stromnetz Berlin, Berlin's power grid operator, which requires the purchase order number and the date or period of service (as of December 2024).

Depending on the client, you also need references for each unit: in metering, for example, the meter number and the metering point ID (Zählpunkt or Messlokation); in fiber, the house connection ID. These should be in the work order before the technician heads out.

For VAT, a monthly invoice is still possible, because an e-invoice may also give the calendar month as the date of supply. But Stromnetz Berlin does not accept invoices with more than one purchase order number. It depends partly on your client whether each unit needs its own line in the XML, or whether one quantity line per type of service is enough, with the unit list attached. Settle this with your client and your tax advisor by mid-December 2026. With every large client, also agree in writing:

the format, XRechnung or ZUGFeRD
the channel, email inbox or portal
which attachments are allowed, and up to what size
whether the acceptance record should be attached

Have the proof for each unit ready when the invoice goes out

In our experience, many companies send the invoice first, and the proof follows when the client asks. With e-invoices, the client can match every line against its purchase order automatically. A quantity or reference that doesn't match can hold up the whole monthly invoice. If you can then send the proof straight away, you keep the delay short.

Tax law does not require the measurement record (Aufmaß) or photos to go with the e-invoice; your contract decides that. Stromnetz Berlin, for example, requires checked and approved measurement records as an attachment, and in a dispute first pays only the undisputed quantities. Under EN 16931, attachments can be embedded as PDF, PNG, JPEG, CSV, XLSX or ODS. XRechnung sets no size limit, but inboxes and portals may have their own. Mandatory details such as quantity and type of service must be in the invoice itself; a link to a portal does not replace them.

We recommend one proof line per unit in the attachment, with these columns:

unit ID
date of work
quantity from the measurement record
accepted (yes or no)
photo reference

Only what is documented, and ideally accepted, by a fixed billing cutoff goes into the monthly invoice. Anything disputed moves to the next month.

The technician lays the groundwork on site, recording:

old and new meter numbers with readings
the measurements, for example trench length per house connection in fiber work
required photos from a fixed list, for example the rating plate and seal, an overview of the installed meter, or the house connection, ideally with no people in the picture
defects and deviations, with a photo

If this data reaches the office the same day, the proof is ready when the invoice goes out.

Acceptance and the final invoice

Under § 640 of the German Civil Code (Bürgerliches Gesetzbuch, BGB), your client, as the party that ordered the work, must accept work that meets the contract. The client may not refuse acceptance because of minor defects. Once the work is finished, you can set a reasonable deadline for acceptance. Unless the client refuses acceptance within that deadline and names at least one defect, the work is deemed accepted (§ 640(2) BGB). With consumers, this only applies if your request for acceptance pointed out these consequences in text form (Textform, for example by email or letter). A resident's signature on the installation report is, as a rule, not acceptance by your client, unless the client authorized the resident to do so or your contract provides for it.

Payment falls due, as a rule, on acceptance. If you work as a subcontractor, it falls due at the latest to the extent that the general contractor has been paid for your work or its own client has accepted the general contractor's work (§ 641(2) BGB).

The rules in § 650g BGB only apply to construction contracts under § 650a BGB. Whether a meter swap or a fiber house connection is one depends on the individual case. Where they apply, a client who refuses acceptance and names defects must, on request, take part in jointly recording the state of the work (Zustandsfeststellung). If the client doesn't turn up on the date set for this, you are, as a rule, allowed to record the state of the work on your own. Under these rules, payment is in principle only due once the work has been accepted and you have issued a verifiable final invoice (prüffähige Schlussrechnung). The invoice is deemed verifiable unless the client raises reasoned objections within 30 days of receipt. In our view, a clean unit list with proof attached makes it hard to dispute that the invoice is verifiable.

Your contract can set different rules for all of this, for example if it validly includes the VOB/B, a standard set of German construction contract terms.

When a client looks shaky

Payments start coming later, and your contact stops calling back. At that point, what counts is what you can prove, because until acceptance it is usually up to you to show that you did the work as the contract requires. What we would do:

Actively ask for acceptance and set a reasonable deadline. Where partial acceptance has been agreed, do this per section or per unit.
Invoice in short cycles, with a verifiable statement of work.
For construction contracts, where applicable, demand security for your payment (Bauhandwerkersicherung) under § 650f BGB, even after acceptance. This does not apply to certain public clients or to consumer construction contracts.
Bring in a lawyer early.

Under § 103 of the German Insolvency Code (Insolvenzordnung, InsO), once insolvency proceedings have been opened over the client's assets, the insolvency administrator decides whether to go ahead with a contract that neither side has fully performed. For work done before the proceedings began, you are, as a rule, left with an insolvency claim, even if the administrator continues the contract (§ 105 InsO). You file that claim with supporting documents (§ 174 InsO). At that stage, a documented acceptance won't get you paid in full, but it does let you prove what you delivered. So once you hear of an insolvency petition, record the state of work on every unit with the date and photos.

How Jarvis helps

Jarvis comes in before the invoice, with the data and proof for each unit. Your invoicing or accounting software still creates the e-invoice itself.

In the Jarvis app, technicians record what will later go into billing, using a report form for each type of work order. For a meter swap, for example, that means the numbers and readings of the old and new meter. This also works offline. Jarvis checks installation photos with AI while the technician is still on site, so that no unusable photo ends up in the proof. Project managers see the complete history of every unit, with photos, in real time. As soon as a unit is completed, its data is ready for billing. Your client's purchase order number can be carried in every work order from import onward. This data can then be passed to your accounting software through the open API and the integrations Grid Jarvis builds with your systems.

If you are reworking your billing right now, we are happy to look at where in your company the proof for each unit comes from. Book a 15-minute walkthrough.

This article is not tax or legal advice. Please ask your tax advisor whether your company must issue e-invoices and from what date, and ask a lawyer about acceptance or insolvency questions.

Sources

By Valter Pasanen, Founder, Grid Jarvis. Published 2026-10-16. 2026-10-16