The customers of real estate broker are the sellers and buyers of the real estate to be sold. The sellers and buyers themselves are the principals (definition 2 in the Principal article) in the sale and real estate agents are their agents (law). However, although a real estate agent commonly fills out the real estate contract form, typically real estates agents are not given power of attorney to sign the real estate contract or the deed; the principals and seller sign these documents, respectively. The respective real estate agents put themselves down on the contract as the agents for each principal so that they may be able to collect their commission(s). The use of a real estate broker is not a requirement for the sale or conveyance of real estate or for getting a mortgage loan from a lender; although once a broker is used, the lender or its attorney will require that they be paid. Lenders typically have other requirements, though, for a loan.