Amendment

A formal, signed change to one or more specific clauses in an existing contract, replacing or modifying the original language.

Example

A fixed-fee contract's payment-terms clause is amended from Net 30 to Net 15 after repeated late payments, via a one-paragraph amendment both parties sign.

Why it matters for agencies

Distinguishing an amendment (changes existing terms) from an addendum (adds new terms) matters legally — using the wrong instrument, or making changes over email without either, is a common way agencies end up with a contract that no longer matches what was actually agreed.