The annual cap is the most a service contract will pay toward covered repairs or replacements within one contract year, as the contract defines that year. It is one of the first figures people compare, and it is also one of the easiest to misread, because the number on a page rarely tells you how much room is left after the first claims.
What the annual cap is
An annual cap is a ceiling on payouts, not a promise of them. A contract with a higher cap can still leave you paying more out of pocket if its service call fee is higher, if its exclusions remove more of your appliances, or if its waiting period delays the first covered visit. Read the cap alongside the other terms in the contract rather than on its own.
A service call fee is the amount you pay at each visit, separate from the repair itself. Whether that fee counts toward the annual cap is a separate question, and the answer changes how much of the cap is really available for repairs.
What can quietly shrink the room
Look for these in the contract wording:
Whether the cap applies to the whole contract or to each appliance. Whether a replacement uses the same pool of money as a repair. Whether taxes, parts, labor, and diagnostic time count toward the cap in the same way. Whether the cap resets at the start of each contract year or at renewal, and whether an unused amount carries forward, which many contracts do not allow.
How to compare it fairly
Put the cap, the service call fee, and the waiting period in one list for each contract you are weighing. Then ask the seller to explain, in writing, what a single expensive repair would leave in the cap after your fees. A plain answer in writing is more useful than a headline figure.
For the published figures this site has gathered for a set of companies, see Twelve home warranty companies compared, term by term. Use that table to line up the terms, then check each one against the contract you are actually being offered, since the offered contract is the one that governs.