Most people read a service contract for what it covers and what it costs. Fewer read it for a clause that lets the seller change the terms later. That clause can matter as much as the coverage itself, because it decides whether the paper you sign is the paper you keep.
What a change clause looks like
Read the contract for words such as may modify, may amend, may update, or reserve the right to change. Some clauses limit changes to rules the law requires. Others allow changes to any term. The gap between those two kinds of clause is the reason for the questions below.
The questions to ask before you sign
Can the seller change any term after I sign? Which terms can change, and which cannot? How is notice given, to what address, and how long before a change takes effect? Can I decline a change, and what happens to my contract if I do? Does a change affect the cancellation refund, the waiting period, the exclusions, or the transfer rule? Who answers my questions about a change, and in what form?
What to do with each answer
Write each answer beside the clause it refers to. A broad right to change, with no notice rule and no right to refuse, is a different paper from a narrow clause that sets notice and allows you to decline. Do not accept an answer that exists only as speech. Ask the seller to put it in writing and to point to the clause that says it.
When a change actually arrives
Keep every notice you receive, including the envelope or message that carried it. Compare the changed term against the original paper. Ask whether the change applies to contracts already in force or only to new sales. If a change narrows coverage or moves cost onto you, the question is the same one you asked before signing, and the answer should be in writing.
What this does not settle
This is a reading guide, not legal advice. Whether a particular change can be enforced depends on the contract's wording and on the state that regulates the seller. The state page on this site names the regulator and the statute, and it says where a state has not been read in this edition. For a specific change, ask the regulator directly or consult a lawyer.