VOB/B principle: No entitlement to remuneration other than the lump sum price

According to § Section 2 (7) sentence 1 VOB/B changes to the contractually agreed price are generally excluded. This means that the client can generally rely on not having to pay more than the agreed total fixed price for the contracted service.

VOB/B exceptions

According to VOB/B, there are the following exceptions to the principle that the lump sum price cannot be changed:

• Unreasonableness of adhering to the lump sum price pursuant to Section 2 (7) No. 1 Sentence 2 VOB/B in conjunction with Section 313 BGB
• Remuneration for additional or modified services in accordance with § 5 in conjunction with § 2 Para. 7 No. 2, § 2 Para. 5, 6 VOB/B
• Subsequent recognition of a service not commissioned by the client pursuant to Section 2 (8) no. 2 sentence 1 VOB/B
• Management without a contract pursuant to Section 2 (8) no. 2 sentence 2, no. 3 VOB/B in conjunction with Sections 677 et seq. BGB

The first two cases deserve special attention:

Unreasonableness of adhering to the flat-rate price

Even in the case of lump-sum prices, the originally agreed price can be changed in accordance with Section 2 (7) No. 1 Sentence 2 VOB/B if the work performed deviates so significantly from the planned work that it is no longer reasonable for one of the parties to adhere to the lump sum. In this case, the unreasonable burden is compensated by granting the additional or reduced costs.

The standard for unreasonableness is derived from Section 313 BGB, the disturbance of the basis of the transaction. This requires a blatant disproportion between the service and the lump sum. Extremely strict requirements are set and an assessment is made depending on the individual case.

The contractor bears the risk for the correct calculation when agreeing a lump sum price; if he could have recognized that his service description was incorrect or incomplete, he cannot subsequently invoke an unreasonable lump sum price. If a “fixed price” has been agreed, there are particularly high hurdles for the contractor to prove an unreasonable burden.

Remuneration for “additional” or “modified” services

A claim to remuneration that can be demanded in addition to the agreed lump sum price is granted by § 2 Para. 7 No. 2 VOB/B, according to which the provisions of § 2 Para. 5, 6 VOB/B (remuneration for additional or changed services) also apply if a lump sum has been agreed.

The decisive factor here is whether the service is actually an “additional” or “modified” service.

This is only the case if the service is not already included in the originally agreed service target. It is disputed who bears the burden of proof that the service is not part of the original performance target.

This question is always determined by what the parties have specifically agreed:

Systematically, a distinction is made between a global flat-rate contract and a detailed flat-rate contract. In practice, there are a large number of mixed forms, so that classification into a pure contract type appears to be rather unusual. However, the classification can provide arguments as to whether a certain service is already contractually owed or not. For the distinction between global flat-rate contracts and detailed flat-rate contracts, please read my separate CONTRIBUTION. The following are therefore only the key points:

Global flat-rate contract

In a global lump sum contract, the service is described functionally and the contractor bears the particular risk of having to supplement the original rough service description in any case.

Detailed flat-rate contract

In a detailed flat-rate contract, on the other hand, it is not the service that is flat-rate but the price. This contract is usually based on a detailed specification of services. The flat-rate price then only includes the services described in the specifications.

Contracts with a so-called completeness clause

In the case of so-called all-inclusive clauses, according to which the contractor is obliged to provide all necessary services without separate remuneration, it depends, according to case law, on who is to bear the risk of unforeseeable services. In the case of detailed flat-rate contracts, the risk should be limited to increased quantities; completely new services should not be borne by the contractor.