Freelancing from office - do I need a contract?

Hi there

I work as a freelance marketing consultant and my recent long term contracts I have worked from the office of the client and been placed via a recruitment agency who gave me a contract to sign etc.

I work as a limited company and usually invoice the recruitment company.

However I have now taken on 2 months work in a "pure freelance" capacity, ie was direct and not through a recruitment agency and will be invoicing the client directly.

This work is office based - I think I should ask them to give me a contract? Would welcome advice on this - but feel a bit "unprotected" if I just go in without a contract.

Also clearly want to set out my payment terms and have that included in the contract as well.

What else should a contract include under these circumstances?

Be grateful for any advice.

Many thanks