A dispute from underground: 812,000 euros in the 29th interim invoice
A construction consortium was securing and backfilling a former underground tunnel system of an asphalt mine for a city. The contract was awarded in June 2023, the VOB/B was incorporated, works started in July 2023. By August 2024 the contractor had invoiced around 20.7 million euros gross. With its 29th interim invoice of August 2024 it claimed a further 812,499.98 euros — and the principal refused payment on two change-order positions: N 1.5 (disposal of surplus drilling water) and N 2 (surcharges after the daily backfilling volume had been reduced).
The contractor went to court on the fast track. The Regional Court of Hanover rejected the application, and the Higher Regional Court of Celle dismissed the appeal by judgment of 14 May 2025 (14 U 238/24), with more than 512,000 euros at stake on appeal. Not because the fast track does not exist — but because the contractor missed its conditions. That failure reads like a step-by-step manual for doing it right.
How the fast track of §§ 650b–650d BGB works
Since 2018 the German Civil Code has contained a system of rules on changes during construction. The principal may demand a change to the agreed works (Änderungsbegehren), the contractor then submits an offer for the additional or reduced remuneration (the change-order offer, or Nachtragsangebot), and if the parties fail to agree within 30 days, the principal may order the change unilaterally in text form (§ 650b(2) BGB).
That is where the mechanism at the heart of this case opens up. First, § 650c(3) BGB: in its interim invoices the contractor may put in 80 per cent of the amount stated in its own change-order offer — without the principal agreeing to the price and without waiting for an expert. Second, § 650d BGB: once construction has begun, an interim injunction over such amounts does not require the ground for the injunction (urgency) to be substantiated — the statute presumes it. That is a powerful exception, because an injunction ordering actual payment (a Leistungsverfügung) means satisfaction before judgment and is normally almost out of reach.
OLG Celle: the route is open under VOB/B too
The first piece of good news from Celle: § 650c(3) and § 650d BGB also apply to contracts incorporating the VOB/B. The VOB/B has its own change regime (§ 1(3) and (4), § 2(5) and (6) VOB/B), but it contains no counterpart to the 80 per cent instalment — § 16 VOB/B governs interim invoices without giving the contractor any provisional right to set the price unilaterally. Since the VOB/B modifies nothing here, the Civil Code provisions continue to apply. The Higher Regional Court of Munich had already ruled the same way (decision of 12 March 2024, 9 U 3791/23).
The second piece of news matters just as much: §§ 650b–650d BGB form one coherent system. Whoever wants the 80 per cent and the presumption of urgency must go through the full sequence of § 650b BGB — change demand, concrete offer, only then the order. And it was this sequence on which the whole case foundered.
Trap one: an offer that reveals no costs
For position N 1.5 the contractor offered the disposal of surplus drilling water “against proof of expenditure, plus the surcharges according to the original calculation”. For the OLG Celle that is not enough. Beyond the general requirements for offers under §§ 145 et seq. BGB, a change-order offer must put the principal in a position to estimate at least approximately what additional costs it faces. The court accepted that no final price could be given before drilling began, since nobody knew how much water would accumulate. But a price list or cost estimate of the disposal company could have been attached: price per tonne, hourly rates. Without such anchor points the principal cannot even roughly tell what it is signing up for.
On top comes a timing rule: the offer must exist in sufficiently definite form before the principal orders the change. Otherwise the contractor could fix the level of its own instalments after the fact with a late offer — precisely what the provision is meant to prevent. Without a proper offer the whole construction collapses: what remains is the ordinary instalment route under § 632a BGB or § 16 VOB/B and ordinary proceedings. How extra work is priced in such proceedings is covered in our article on pricing and documenting change orders.
Trap two: the change must concern the works, not the circumstances
For position N 2 the contractor argued that the principal had reduced the daily backfilling volume (from 260 m³ per day and station), cutting efficiency and driving up costs. The OLG Celle did not even have to decide whether such an order was given. § 650b BGB covers only changes to the content of the works — the agreed result or the services needed to achieve it (the so-called Bauinhalt). Orders concerning merely the circumstances of performance, above all construction time and pace (the Bauumstände), fall outside the provision altogether.
It did not even help that the principal itself had recorded in a site meeting protocol that “change order 2 is undisputed in its necessity”. If objectively there is no change within the meaning of § 650b BGB, an order runs into the void as a so-called putative change order — and creates no claim under § 650c BGB. Costs caused by longer construction time or lower productivity must be pursued on other legal bases, in ordinary proceedings.
Trap three: whoever waits rebuts the urgency presumption himself
The presumption of urgency under § 650d BGB does not last forever. The OLG Celle applies a principle known from unfair-competition law: whoever fails for an unreasonably long time to use the available fast-track protection shows that the matter is not urgent to him (self-rebuttal). How long one may wait depends on the circumstances — but the case law generally allows one to two months, with the upper limit at two, at most three months from the moment it is clear that no agreement will be reached.
In this case the principal had never paid anything on N 1.5 since July 2023, had paid nothing at all on the disputed positions since the 22nd interim invoice of May 2024, and had refused recognition repeatedly and in writing. The contractor filed its application only months later — for N 1.5 more than a year later. The presumption was gone. The OLG Celle also expressly rejected the more generous Berlin line, under which the mere fact that a claim remains unpaid keeps it urgent.
One important caveat: missing this window does not destroy the claim itself. Only the fast track is lost — the money can still be pursued in ordinary proceedings within the ordinary limitation periods.
Trap four: claims based purely on the VOB/B do not enjoy § 650d
The final holding hurts the most in practice. The urgency presumption covers only disputes over orders under § 650b BGB and the remuneration adjustment under § 650c BGB. Disputes over orders under § 1(3) and (4) VOB/B, over the calculation of change-order remuneration under § 2(5) and (6) VOB/B, and claims resting on any other basis are not covered. Whoever builds the application purely on the VOB/B must satisfy the general requirements for a payment injunction, and those are strict: a threat of existential, irreversible harm, or a situation in which referring the creditor to ordinary proceedings would amount to a denial of justice.
A general reference to rising costs and shrinking liquidity — which is what the contractor in Celle offered — is not enough. One would have to show, for instance, a real threat of insolvency. The practical lesson: the legal basis on which you rest your claim decides whether you enjoy the presumption of urgency.
Before you file for an interim injunction
The § 650b BGB sequence documented: a written change demand from the principal, then your change-order offer with specifics (unit prices, hourly rates, the subcontractor’s price list), only then the order. The change concerns the content of the works, not merely deadlines or pace. The amount in the interim invoice: 80 per cent of the change-order offer. The claim rests on § 650c BGB, not solely on § 2 VOB/B. The application goes in no later than two months after the clear refusal to pay — every further week works against you.
What this means for your company
- Build the sequence from day one. Change demand in writing, concrete offer, only then the order. Without this order of events the 80 per cent instalment is gone before you think of it.
- Write change-order offers that can be calculated. Described services plus a final price, or verifiable foundations: unit prices, rates, a third party’s price list. A bare “against proof of expenditure, plus surcharges from the calculation” will not survive court scrutiny.
- Distinguish the content of the works from the circumstances. Design changes and additional services — fast track. Changes to pace, deadlines or site organisation — ordinary claims and ordinary proceedings.
- Count time from the refusal, not from the invoice. One to two months to decide, after two to three the urgency presumption evaporates. The claim survives, the fast track does not.
- Have a plan B. If the fast track is out, there remain ordinary proceedings and the § 650f BGB payment security, which covers change orders too. Details in our article on extra work, and on the final account in the piece on the final invoice (Schlussrechnung).
Frequently asked questions
How does an interim injunction differ from an ordinary payment action?
In speed and character. An ordinary construction case takes years, an interim injunction is decided in weeks. For claims under § 650c BGB, once construction has begun, urgency does not have to be substantiated. The title is provisional — the dispute on the merits may continue, but the money arrives earlier.
How much time do I have to file?
The case law generally allows one to two months from the moment it is clear the principal will not pay, with the upper limit at two to three months. In the OLG Celle case the contractor waited more than a year and the presumption of urgency fell. The claim itself can still be pursued in ordinary proceedings.
Does the fast track work under a VOB/B contract?
Yes. The VOB/B contains no counterpart to § 650c(3) BGB or § 650d BGB, so both provisions apply in VOB/B contracts as well — so the OLG Celle and before it the OLG Munich. The condition is the full § 650b BGB sequence: change demand, offer, order.
How concrete must the change-order offer be?
Concrete enough for the principal to estimate the additional costs at least approximately: described services plus a final price, or verifiable foundations — unit prices, hourly rates, a subcontractor’s price list. And always before the change is ordered, not after.
The principal tells me to slow down or moves deadlines — can I claim the 80 per cent instalment?
Not by this route. Orders concerning only construction time and the circumstances of performance do not fall under § 650b BGB, even where they genuinely increase costs. Such claims are pursued on VOB/B bases in ordinary proceedings — without the presumption of urgency.
This overview draws on the judgment of the OLG Celle of 14 May 2025 (14 U 238/24, first instance: LG Hannover, 7 O 151/24), the decision of the OLG Munich of 12 March 2024 (9 U 3791/23), the decision of the OLG Karlsruhe of 23 September 2022 (8 W 29/22) and the judgment of the KG of 7 September 2021 (21 U 86/21), as well as §§ 650b–650d BGB, §§ 935, 940 ZPO and § 1(3), (4), § 2(5), (6) and § 16 VOB/B. This article is for information purposes and does not replace legal advice in an individual case.