The client commissioned the change order orally. Is that enough?

Legally, an oral agreement can also be binding — but you have to prove it. For a UNILATERAL instruction under § 650b Abs. 2 BGB, the law expressly requires text form. You should therefore briefly confirm every oral instruction in writing, asking for any objection by a set date. This costs nothing and is often the decisive evidence in a dispute.

What is the difference between changed and additional work?

With changed work (§ 2 Abs. 5 VOB/B), agreed work is carried out differently; with additional work (§ 2 Abs. 6 VOB/B), something is added that was not provided for in the contract at all. The difference matters in practice: only for additional work is the announcement before execution a precondition of the claim.

Do I have to pre-finance the change order until the final invoice?

No. After an instruction under § 650b Abs. 2 BGB, you can demand 80 percent of the additional remuneration stated in an offer as an installment payment (§ 650c Abs. 3 BGB). This is one of the most important practical levers of BGB construction contract law and is rarely used.

The client says it was all included in the offer. What now?

Then the dispute is not about the price but about the agreed scope of work. Quote the relevant item of the bill of quantities verbatim and set against it what was actually required. Only once this boundary is established does a change order calculation have any point of reference at all.

May I stop work until the change order is paid?

Only on a verified basis. Stopping work without a right of retention is itself a breach of contract and can give the client a right to terminate. The intended route is instead the security for construction work under § 650f BGB — there the order of the steps is decisive and should be checked by a lawyer.

SMBs & agencies · Change order disputed

Change order submitted, client will not pay — additional remuneration under §§ 650b, 650c BGB

The client wanted it done this way — but does not want to pay for it. Whether you enforce the change order (Nachtrag) is usually decided by two formalities, not by the price.

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Deadline at a glance

Announce additional work BEFORE carrying it out

§ 2 Abs. 6 Nr. 1 VOB/B

For additional work under § 2 Abs. 6 VOB/B there is no deadline in days but a point in time: the announcement must be made BEFORE work begins, otherwise the right to remuneration lapses. Under a BGB construction contract, the procedure of § 650b BGB applies instead — a 30-day attempt to reach agreement, then an instruction in text form.

It is an AI, not a person: nobody looks at your individual case, and we do not know who signs up or for what reason. That is why we give pointers, but no legal advice on the individual case. Guidelines and playbooks in the platform are only guardrails: the AI relies on the available sources and your information. AI can make mistakes — check important results, and if in doubt, ask a lawyer.

Typical risks in this scenario

What we pay special attention to

Curated from real cases. The AI review flags exactly these points in your document.

Additional work carried out without announcing it beforehand — under § 2 Abs. 6 VOB/B the announcement is a prerequisite for the claim.
Instruction given only orally: § 650b Abs. 2 BGB requires text form, and clients regularly dispute oral agreements.
The client considers the work covered by the original bill of quantities — then there is no variation, only performance.
Lump-sum contract: there the contractor bears the quantity risk; mere additional effort without a change to the agreed scope of work does not justify additional remuneration.
Extension of the construction period and disruption damages included in the variation price — these are separate claims (§ 6 VOB/B, § 642 BGB) with their own requirements.
Work stopped because of a disputed variation, without a right of retention or the procedure under § 650f BGB — this can justify termination by the client.
Variation claimed only after the final payment was accepted without reservation (§ 16 Abs. 3 VOB/B).
No verifiable calculation: without comprehensible quantities, unit prices and surcharges, the claim does not fall due.

What you can do here in 5 minutes

Change orders (Nachträge) rarely fail because of the calculation and almost always because of form. Under a VOB/B contract, remuneration for additional work requires that you announced it BEFORE carrying it out (§ 2 Abs. 6 Nr. 1 VOB/B). Under a BGB construction contract, the client's unilateral instruction (Anordnung) must be in text form (§ 650b Abs. 2 BGB) — and it is preceded by an attempt to reach agreement lasting 30 days. Once the instruction is in place, remuneration is based on the costs actually required plus reasonable surcharges (§ 650c Abs. 1 BGB), and you can immediately demand 80 percent of the additional remuneration offered as an installment payment (§ 650c Abs. 3 BGB).

Upload the construction contract, the bill of quantities, the correspondence on the instruction and your change order offers — we assign each change order to the correct legal basis, check text form and the announcement, compare the agreed scope of work with the work actually required and draft the change order letter.

How it works

Results in three steps

Upload your documents

Construction contract, bill of quantities, correspondence on the instruction, change order offers.

Determine the legal basis

An instruction under § 650b BGB, changed or additional work under § 2 VOB/B — or no change order at all?

Draft the change order letter

Agreed scope and additional work compared side by side, installment under § 650c Abs. 3 BGB, payment deadline with a date.

What you get

Upload your documents – Construction contract, bill of quantities, correspondence on the instruction, change order offers.
Determine the legal basis – An instruction under § 650b BGB, changed or additional work under § 2 VOB/B — or no change order at all?
Draft the change order letter – Agreed scope and additional work compared side by side, installment under § 650c Abs. 3 BGB, payment deadline with a date.

What it is not

No calculation of the change order price — only you know the costs actually required, and their amount is the real point of dispute.
No binding interpretation of whether work is still covered by the bill of quantities; that is often a question for an expert.
No proof of instructions given orally.
No verifiable change order calculation to VOB standards and no representation in court.

FAQ

Common questions about this case

Transparency

What the AI checks — and what only a lawyer can decide

An AI is only as good as the question. We show openly where your answer is reliable and where you should speak with a lawyer.

If the client denies having instructed anything at all, for disputed change orders above around €25,000, if construction time and a contractual penalty are disputed at the same time, or before you demand security for construction work (Bauhandwerkersicherung) under § 650f BGB or stop work, you should involve a lawyer specializing in construction and architects' law.

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