E-Invoicing 2027: Client Questions in the Firm Chat

The general transition period for paper invoices ends at the turn of the year. A firm chat answers standard questions from the memo and hands over the rest.

In plain language

For invoices between firms in Germany, a transition period is ending. Smaller firms have one more year. Questions about this pile up toward the end of the year. Whether a rule fits a client is for the firm to check, not the chat. The chat only gives facts from the firm's client memo. It asks for a few rough key facts. From this it makes a prepared request for a meeting. When the rules change, the memo is updated.

October 7, 2026 15 min read By XICBOT

Key points

On 31 December 2026 (Section 27 (38) UStG) the general transition period for paper and other invoices between domestic businesses ends. The questions it raises arrive bundled in the fourth quarter and can be planned for.
Businesses whose total turnover in the previous year was no more than EUR 800,000 (Section 27 (38) UStG) may keep invoicing that way until 31 December 2027. Whether that applies is for the firm to decide, not the chat.
Information from the firm's client memo is information. Reviewing whether a rule fits a particular client is assistance in tax matters (Section 2 (2) StBerG) and stays with the licensed professional.
The assistant asks for a few rough key facts: customers are businesses or consumers, turnover band, type of invoicing tool. The result is a prepared meeting request instead of a call-back without context.
The only basis for answers is the firm's approved client memo. When the rules change, the memo is updated, and after the next refresh the assistant answers on the new basis.

Why e-invoicing questions arrive bundled in autumn

The move to electronic invoicing is happening in stages. For supplies between domestic businesses, Section 14 (2) UStG makes the electronic invoice the standard case; the transitional provision in Section 27 (38) UStG, however, still allows paper and other electronic formats for transactions from 2025 and 2026. This general relief expires on 31 December 2026 (Section 27 (38) UStG). For businesses whose total turnover in the previous calendar year was no more than EUR 800,000, it continues to apply to transactions from 2027, namely until 31 December 2027 (Section 27 (38) UStG). A third case concerns invoices sent through an electronic data interchange procedure, EDI for short; a special rule applies to these as well until the end of 2027, provided the recipient agrees.

For a firm, this means that every client who issues invoices should know by the turn of the year which group they belong to. Most of them hear about it from the client newsletter, from the trade press or from the provider of their invoicing program - and many then pick up the phone because they want a quick confirmation. The wave of enquiries therefore has the same shape as any seasonal peak: it is predictable, it is large, and most of it consists of questions that a good memo can answer. We described in general terms how to absorb such peaks in chat in the article on peak-season support spikes; the same pattern shows up this autumn in the tyre-changing season at garages.

The difference from a garage or an online shop lies in the line a tax firm has to draw. An assistant may explain what the law says and what the firm writes about it in its client information. It may not decide whether a rule applies to a particular client. This is exactly where an enquiry the assistant answers in full separates from one it prepares and hands over to a person.

NoteIn brief: what changes at the turn of the year

Under Section 14 (1) UStG, an electronic invoice is an invoice that is issued, transmitted and received in a structured electronic format and allows electronic processing. A file that only shows an image of the invoice does not meet this; like paper, it counts as an other invoice. The electronic invoice is mandatory for supplies to other businesses when both are established in Germany (Section 14 (2) UStG). This obligation does not apply to supplies to consumers. Invoices for transactions from 2025 and 2026 may still be sent on paper or - with the recipient's consent - in another electronic format until 31 December 2026 (Section 27 (38) UStG). For transactions from 2027, this only applies if total turnover in the previous year was no more than EUR 800,000, or if the invoice is transmitted via EDI.

The questions clients actually ask at the turn of the year

Anyone in a firm who goes through the phone notes of an autumn will find a manageable number of core questions. They come in different words but with the same core. For setting up an assistant, this list is the most important step, because it determines which answers the memo must contain and at which point the assistant stops explaining.

Does this affect me at all? The most frequent question. It depends on whom the client invoices and whether their transactions are taxable. The assistant explains the criteria and asks; the firm does the classification.
Can I still send paper invoices from January? Behind this is the turnover threshold of EUR 800,000 (Section 27 (38) UStG). The assistant states the threshold and the deadlines from the information sheet but does not confirm that a particular client is below it. The law firm template excludes statements on deadlines by default; the firm can lift this restriction in the assistant's settings.
Is a PDF invoice sent by email an e-invoice? Not if it only contains an image of the invoice. This can be answered in general terms, because the definition is in the law.
Which format do I need? The law refers to the European standard on electronic invoicing. Which formats the firm recommends to its clients is in the memo; the assistant repeats exactly that.
Do I also have to be able to receive e-invoices? Anyone buying from domestic businesses should be set up for it: where the e-invoicing obligation applies, the sender does not need the recipient's consent (Section 14 (1) UStG). For many clients, this is the real surprise.
What about small amounts and small businesses? Invoices whose total amount does not exceed EUR 250 (Section 33 UStDV) and invoices from small businesses (Section 34a UStDV) may be transmitted as other invoices, by way of derogation from the obligation. The assistant repeats this from the memo; whether a client is a small business is clarified by the firm.
What exactly do I need to change in January? The question where every general answer ends. The answer depends on software, customer base and turnover - and therefore on the individual case.

Most of these seven questions can be answered in general terms, and only a small share necessarily leads to a review. This ratio is the core of the idea: if the assistant answers the general questions in full and passes the rest to the firm with the right key facts, the calls that only seek confirmation can decrease, and every remaining enquiry arrives prepared.

Where the line runs: information yes, individual case no

The Tax Advisory Act draws the line more precisely than it is often perceived in day-to-day practice. Under Section 2 (2) StBerG, assistance in tax matters is any activity in the affairs of others as soon as it requires a legal review of the individual case. It may only be provided on a business basis by persons and associations authorised to do so (Section 2 (1) StBerG). For an assistant on a firm's website, this results in a clear division of roles: it repeats what applies in general, and it collects what the adviser needs for the review. It does not take on the review itself - not even when the client has already supplied all the details and the answer seems obvious.

In practice, the line can be recognised by the wording. The question of until when paper invoices are generally permitted can be answered from the law. The question of whether a particular client's joinery was below or above the turnover threshold in 2026 requires figures from the accounts, knowledge of special cases and an assessment. It is similar with tax-exempt supplies: the obligation to issue an invoice under Section 14 (2) UStG only applies if the transaction is not tax-exempt under Section 4 nos. 8 to 29 UStG. Which of a client's transactions fall under this is a question for the adviser, not for the chat.

Explain in general

Deadlines, turnover threshold, definition of the e-invoice, receipt and format: the assistant repeats what is in the law and in the firm's memo, and names the statutory reference.
Do not classify

Whether a client falls below the threshold, whether their transactions are tax-exempt or whether their software is sufficient is not meant to be assessed by the assistant, not even as a tendency. That review belongs to the licensed professional.
Prepare the meeting

Instead, it records the key facts, summarises them for the adviser and offers a meeting. The conversation starts with knowledge of the case, not with the same follow-up questions.

These three roles apply to firms that use an assistant, whatever the topic. In principle they are the same ones we described for new-matter enquiries in the article on the AI assistant for law firms; there the question was whether an enquiry belongs to employment, tenancy or family law. With e-invoicing, the subject is narrower and the deadline is fixed, which makes the setup simpler: the list of general answers is short, and the criteria for a handover can be defined in advance.

A good refusal includes the next step

An assistant that only dodges the question about the client's own case creates a second call. A better answer explains what applies in general, says who decides on the individual case and offers the meeting in the same breath. For example: under Section 27 (38) UStG, the extended period until the end of 2027 applies to businesses whose total turnover in the previous year was no more than EUR 800,000. Whether that applies to you is reviewed by your adviser on the basis of your figures; I will note your details and suggest a meeting.

Which key facts the assistant asks for before the meeting

Pre-sorting is the part that saves the firm the most time, and at the same time the part where the most can go wrong. The assistant should know enough for the adviser to prepare, and ask for so little that nobody discloses their accounts in the chat. A few rough details that the client can answer without documents are sensible.

Customer base: Does the client invoice mainly other businesses, mainly consumers, or both? The obligation under Section 14 (2) UStG only applies to supplies to businesses.
Turnover band: Was total turnover in the previous year roughly below or above EUR 800,000 (Section 27 (38) UStG), or is that unclear? A band is enough; an exact figure is not needed.
Tax-exempt transactions: Are there supplies the client considers tax-exempt, for example as a healthcare profession or in letting property? The detail is noted, not confirmed.
Invoicing tool: How are invoices created today: with an invoicing program, from the merchandise management system, with a text template or by hand? The type of tool is enough for the preparation.
Receipt: Can the business already accept and process e-invoices from suppliers today, or do they end up as unreadable files in the inbox?
Topic and time window: What should the meeting be about, and when would it suit? This becomes the meeting request.

These details do not produce a recommendation but a summary that lands with the responsible person in the firm's system or by email. What such a handover looks like and which fields it should carry is described in the article on handover to human agents; the logic of pre-qualification is the same as when qualifying leads via chat, only with different criteria.

Aspect	Phone and email	Firm assistant
Question in the evening	Waits until the next working day	Answered from the memo
General deadline question	Ties up a specialist for a standard answer	Answer with the statutory reference
Question about own case	Call-back without context	Key facts recorded, meeting suggested
Turnover threshold	Client states a figure on the phone	Turnover band noted as a detail, not assessed
Legal status	Specialists explain it in different ways	One maintained source for all answers
Evaluation	Which questions came up often remains unclear	Recurring questions reveal gaps in the memo

From the chat to the advisory meeting

The meeting is the end point of every enquiry that goes beyond general information. A booking assistant offers free times from the appointment types the firm has set up, lets the client choose one and attaches the summary to the appointment request. The office confirms it in its own view; the assistant only creates an entry in the firm's calendar when a calendar is connected.

In the fourth quarter, it pays to create dedicated meeting types for this: a short conversation for classification and a longer one for changing the invoicing process. The assistant pre-selects the right type based on the key facts, and the firm retains control over how many slots it releases. This spreads the wave over the weeks until the turn of the year instead of letting it pile up in the last days of December.

One particularity of e-invoicing is that the enquiries come mostly from existing clients. The assistant therefore not only has to pre-qualify prospects but also recognise clients who are already being looked after and route them to the right person. The simplest way is to ask for the responsible adviser. A client number can serve as a voluntary aid for assignment; it is not verified in the chat.

An assistant that confirms in the chat that a client is below the turnover threshold has not answered faster; it has taken on a review it is not entitled to. The line belongs in the concept, not in the rework.

Principle from setting up assistants for law and tax firms

Where the assistant's answers come from: the firm's client memo

The quality of the general answers depends on a single source: the memo the firm writes for its clients anyway. The assistant is trained only on it and on the approved pages of the firm's website, and its answers are bound to exactly these sources. What is not in them it should not fill in from general knowledge but pass on to the firm as a question. How this binding to your own content works technically is described on the knowledge base page; why it helps against invented answers is covered in the article on grounded answers.

For e-invoicing, the memo should contain at least these building blocks:

The definition of the electronic invoice and the difference from an other invoice, with the reference to Section 14 (1) UStG.
The deadlines and groups from Section 27 (38) UStG: general end date, turnover threshold, EDI procedure.
The formats the firm recommends to its clients, and notes on further processing in the accounts.
The note on receipt: what clients should do so that incoming e-invoices do not sit unprocessed in the inbox.
The special cases the firm wants to name itself, such as small amounts (Section 33 UStDV) or small businesses (Section 34a UStDV), each with the sentence that the classification takes place in the meeting.
The route to the meeting: which meeting types exist and what clients should bring.

The second advantage of this binding shows when something changes. Besides the law, guidance from the tax authorities may be added or amended. Once the memo is updated, the assistant answers on the new basis after the next refresh. Who is responsible and how often it is checked should be decided before launch; how this can be organised is described in the article on keeping the knowledge base up to date.

Confidentiality, data protection and hosting

A tax firm is bound by a duty of confidentiality that goes further than data protection. Two principles follow for the assistant. First, it only asks for what is needed to prepare the meeting: no tax number, no turnover figures, no uploaded invoices. Second, the service provider operating the assistant is contractually bound to confidentiality. The professional rules for tax advisers govern this expressly: the contract with the service provider must be in text form, and it must bind the service provider to confidentiality, with instruction on the criminal consequences of a breach of duty (Section 62a StBerG).

Data processing runs under a data processing agreement, conversation data is deleted after a defined period, and operation takes place with hosting in Germany. The details are on the privacy and hosting page; we covered the fundamental questions in the article on GDPR-compliant AI assistants. The assistant states at the start of the conversation that the client is writing with an AI system; there is a separate article on labelling obligations covering transparency duties.

A roadmap to the turn of the year

For the assistant to absorb the wave this year, it should be live before the peak. A realistic sequence has five steps:

Collect questions: Go through phone notes and emails from recent weeks and gather the recurring questions about e-invoicing.
Approve the memo: Add the missing answers to the existing client memo and have it approved by a licensed professional.
Define handover criteria: Decide for which questions the assistant stops answering in general terms and instead records key facts and offers a meeting.
Create meeting types: Release a short classification call and a detailed changeover consultation as separate types with fixed quotas.
Test and evaluate: Test with real questions from the firm's daily work, then go live and evaluate the conversations of the first weeks.

The evaluation is not a by-product. Conversation analytics shows which questions were asked often and where answers are missing from the memo. For a firm, this is also a picture of which client groups are not yet prepared - information that can be used for the next newsletter or for targeted calls.

What remains after the turn of the year

The topic is not settled on 31 December 2026. For businesses below the turnover threshold, the same question comes up again for 31 December 2027 (Section 27 (38) UStG), and the first incoming e-invoices raise new questions about further processing. An assistant set up for the first deadline can be reused for the second with a few changes to the memo.

Beyond that, the structure remains: an assistant that answers general questions from approved content, records key facts and prepares meetings also works for other recurring topics in a firm. Which tasks it can take on there is shown on the industry page for the firm assistant. If you would like to go through your own client information, you can reach us via contact; we will look at your existing memo and show in a free demo what answers and handover would look like for your firm.

For clients, one thing above all changes: they get an answer with a statutory reference to the general question without waiting for a call back, and an appointment request with a summary for the personal question, instead of calling twice. For the firm, there are fewer interruptions in daily business and conversations that start with knowledge of the case. How a firm assistant sorts first enquiries and takes appointment requests is shown on the page on the assistant for law and tax firms.

Frequent questions

May a chat assistant answer questions about e-invoicing?

It may explain in general what is in the law and in the firm's memo: deadlines, turnover threshold, definition and receipt. Reviewing whether a rule applies to a particular client is assistance in tax matters under Section 2 (2) StBerG, because it requires a legal review of the individual case. That review stays with the licensed professional; the assistant prepares it and offers a meeting.

Until when may businesses still send paper invoices?

Under Section 27 (38) UStG, invoices for transactions from 2025 and 2026 may be sent on paper or, with the recipient's consent, in another electronic format until 31 December 2026. For transactions from 2027, this only applies until 31 December 2027 if total turnover in the previous year was no more than EUR 800,000, or if the invoice is transmitted via EDI. Whether a client qualifies is clarified by the firm in a meeting.

What happens if a client states their turnover figures in the chat?

The assistant is not meant to assess them. It only notes whether turnover is roughly below or above the threshold or whether that is unclear, and passes this detail on to the firm. Exact figures, tax numbers or invoice files do not belong in the chat; the assistant points out that the firm will take them in the meeting or via its secure exchange channel.

How does the assistant know what it may answer?

From the firm's approved memo and the pages of its website. In addition, handover criteria are defined during setup: questions for which it stops answering in general terms and instead records key facts and suggests a meeting. The firm checks both before launch with real questions from daily work.

How does a chat assistant fit with the firm's duty of confidentiality?

The assistant only asks for what is needed to prepare the meeting. The operator is contractually bound to confidentiality as a service provider, data processing runs under a data processing agreement, and hosting takes place in Germany. The conditions under which tax advisers may involve service providers are set out in Section 62a StBerG.

Is an assistant only worthwhile for the e-invoicing deadline?

E-invoicing is a good occasion because the questions arrive bundled and predictably. But the structure of general information, key facts and meeting also works for the extended period until the end of 2027 and for other recurring topics in a firm. The memo is extended; the assistant stays the same.

Ask it yourself, Assistant of this website

Automated assistant

Settings