My consultancy company, through which I work, has received a modified/replacement contract covering an existing arrangement and about which some things are unclear.

The work arrangement, wholly within the UK under English law, is that my company, 'company A', performs work for and is paid by 'company B' (who issues the contracts,) and the services and consultancy are delivered wholly to/at 'company C'. The following questions of course look at the clauses in isolation and not at all the relevant contractual details, but these are the particular points that need clarifying.

First, in the modified/replacement contract, company A is asked to agree that the Hirer (Company C) is your client or customer for all purposes in relation to work undertaken. At first sight I am having difficulty grasping how there can be a client/customer with whom there is no contractual or financial relationship.

My first question is that does agreeing to this legally change the nature of the relationship between companies A and C, and if so, do we now need a contract between A & C to reflect that change and what should it cover?

Secondly, there is a clause which states in the event of breach of this agreement by the Company the (individual(s) delivering the service/consultancy on behalf of company A) shall, upon receipt of a written request from us, perform or discharge the obligations of the Company due under or arising from this agreement,. The individuals specified may be employees or subcontractors of company A, and the contract further states that they shall not be considered employees of company B.

Is this 'perform or discharge' clause enforcable by company B, and if it is enforced, does it not invalidate the 'shall not be considered employees' clause and consequently none of the contract is enforcable against any of the individuals?