A commercial contract should meet two objectives: the first is that it must simultaneously advance and protect your business interests. The second, and often overlooked goal of a properly drafted commercial contract, is that it should not unduly disturb or endanger the commercial arrangement that the two contracting parties have struck.
In its simplest form, a written contract shows what one party will do for another and what it can then expect in return. As far as possible it should set out the agreement between both sides, what they can expect when things go well and how to solve problems when things don’t. A well drafted contract can make litigating easier or remove the need to litigate at all.
In the absence of a written contract, the parties if they can prove a binding agreement exists, are left to claim for a reasonable price for goods and services supplied and accepted.