(1) Section 305 subsections (2) and (3), section 308 no. 1 and numbers 2 to 9, and section 309 do not apply to standard business terms that are used in contracts with a trader, a legal person under public law or a special fund under public law. Section 307 (1) and (2) nevertheless applies to the cases governed by sentence 1 insofar as this leads to the ineffectiveness of the contract provisions set out in section 308 no. 1 and numbers 2 to 8, and section 309; reasonable account is to be taken of the practices and customs that apply in business dealings. In the cases governed by sentence 1, section 307 (1) and (2) as well as section 308 nos. 1a and 1b do not apply to contracts in which the entire Award Rules for Building Works, Part B (Vergabe- und Vertragsordnung für Bauleistungen Teil B - VOB/B) in the version applicable at the time of conclusion of the contract are included without deviation as to their content, relating to an examination of the content of individual provisions.
(2) Sections 308 and 309 do not apply to contracts of electricity, gas, district heating or water suppliers for the supply of electricity, gas, district heating or water from the supply grid to special customers to the extent that the conditions of supply do not deviate, to the disadvantage of the customer, from ordinances on general conditions for the supply of standard-rate customers with electricity, gas, district heating and water. Sentence 1 applies accordingly to contracts for the drainage of sewage.
(3) In the case of contracts between a trader and a consumer (consumer contracts) the rules of this Division apply subject the following provisos:
1. Standard business terms are deemed to have been presented by the trader, unless they were introduced into the contract by the consumer;
2. Section 305c (2) and sections 306 and 307 to 309 of this Code and Article 46b of the Introductory Act to the Civil Code (Einführungsgesetz zum Bürgerlichen Gesetzbuche) apply to pre-worded terms of contract even if the latter are intended only for non-recurrent use on one occasion, and to the extent that the consumer, by reason of the pre-worded text, had no influence on their contents;
3. in judging an unreasonable disadvantage under section 307 (1) and (2), the other circumstances attending the conclusion of the contract also are to be taken into account.
(4) This Division does not apply to contracts in the field of the law of succession, family law and company law or to collective agreements and private-sector works agreements or public-sector establishment agreements. When it is applied to employment contracts, reasonable account is be taken of the special aspects that apply under labour law; section 305 (2) and (3) is not to be applied. Collective agreements and private-sector works agreements or public-sector establishment agreements are equivalent to legal provisions within the meaning of section 307 (3).