Persuasive evidence of a side agreement is subject to the same standard as the primary arrangement. If the company’s standard practice is for both parties to the arrangement to sign a written contract, then persuasive evidence of a side agreement only exists if both parties have signed a written agreement. If the company does not use a written agreement as standard practice, then persuasive evidence of a side agreement can be demonstrated through other means such as a purchase order, email confirmation, or online order form so long as a binding agreement is created as a result.
A side agreement can take a number of different forms. Frequently, a company will use a standard template as the agreement for the primary arrangement and an addendum to set out specific terms such as consideration, cancellation provisions, payment timing and other matters. There may also be negotiated terms that are in emails or communications between the companies. It is important that these additional terms be documented in a format that is consistent with the company’s standard practice as noted above.