If you run a business as a sole proprietorship, it would be appropriate to be identified in the contract as John Jones doing business as Jones Plumbing. If you organized your business as a Limited Liability Company, identifying your participation in the contract by your name could remove any personal liability protection that an LLC provides. Similar issues can arise with a partnership if each individual is identified as a party to the contract.
Sign and Date the Contract - "If an entity is a party to a contract, it is imperative that the signature block properly identifies the party signing on behalf of that entity," writes Michigan attorney Michael J. Hamblin in his website's article How to Properly Sign a Contract so It Will Be Enforceable. The signature block should name the entity, then under the signature, the name and title of the person signing, such as: Jones Plumbing, LLC By: John Jones Manager. Each signee should include the date next to the signature.