3.2 Number of independent claims 

According to Rule 43(2), as applicable to all European patent applications, the number of independent claims is limited to one independent claim in each category.

Exceptions from this rule can only be admitted in the specific circumstances defined in sub-paragraphs (a), (b) or (c) of this rule, provided the requirement of Art. 82 with regard to unity is met (see F‑V).

The following are examples of typical situations falling within the scope of the exceptions from the principle of one independent claim per category:

(i)Examples of a plurality of interrelated products (Rule 43(2)(a))

–plug and socket 

–transmitter – receiver 

–intermediate(s) and final chemical product 

–gene – gene construct – host – protein – medicament 

For the purpose of Rule 43(2)(a), the term "interrelated" is interpreted to mean "different objects that complement each other or work together". In addition, Rule 43(2)(a) can be interpreted as covering apparatus claims, since the term "products" is considered to include apparatuses. Likewise, it may include systems, sub-systems and sub-units of such systems, as long as these entities are interrelated. Interrelated methods claims may also fall under the exception of Rule 43(2)(a).

(ii)Examples of a plurality of different inventive uses of a product or apparatus (Rule 43(2)(b))

–claims directed to further medical uses when a first medical use is known (see G‑II, 4.2)

–claims directed to the use of compound X for multiple purposes, e.g. for cosmetically fortifying hair and for promoting hair growth 

(iii)Examples of alternative solutions to a particular problem (Rule 43(2)(c))

–a group of chemical compounds 

–two or more processes for the manufacture of such compounds 

(iv)Examples of allowable claim types 

–Claims directed to multiple methods involving a novel and inventive polypeptide P, e.g. an enzyme that controls a specific step in the synthesis of a compound: 

a method for manufacturing the polypeptide P,

a method for manufacturing the compound by using either the isolated polypeptide or host cells expressing said polypeptide,

a method for selecting a host cell based on whether or not it expresses the polypeptide of the invention.

–A data sending method for sending a data packet between a plurality of devices coupled to a bus; 

a data receiving method for receiving a data packet between a plurality of devices coupled to a bus.

–Methods of operating a data-processing system comprising steps A, B, … – a data-processing apparatus/‌system comprising means for carrying out said method – a computer program [product] adapted to perform said method – a computer-readable storage medium/data carrier comprising said program; 

Note however that when several independent claims are directed to equivalent embodiments that are not sufficiently different (e.g. computer program adapted to perform said method, optionally carried on an electric carrier signal – computer program comprising software code adapted to perform method steps A, B …), the exceptions under Rule 43(2) usually do not apply.

For the purpose of Rule 43(2)(c), the term "alternative solutions" can be interpreted as "different or mutually exclusive possibilities". Moreover, if it is possible to cover alternative solutions by a single claim, the applicant should do so. For example, overlaps and similarities in the features of the independent claims of the same category are an indication that it would be appropriate to replace such claims with a single independent claim, e.g. by selecting a common wording for the essential features (see F‑IV, 4.5).