I buy cover on every trip I book for clients, and the policies that disappoint people are the ones bought on price alone. These are the seven checks I run against the wording before a policy goes anywhere near a card, in the order that finds the problems fastest.
The seven checks

Medical and evacuation limits, in writing
Two separate numbers, both high enough for where you are going. I want at least two hundred thousand dollars of medical and a hundred thousand of evacuation, higher for remote coastlines and anything involving a small ship, because a boat-to-hospital transfer is billed before you see a quote.
The list of covered reasons
Cancellation cover is a list, not a principle. Read which reasons are named: illness, bereavement, jury duty, a job loss with conditions, a named natural event. Anything not on the list is not covered, and the marketing summary on the front page will not tell you that.
The pre-existing condition window
Many policies exclude conditions diagnosed or treated inside a lookback period, commonly ninety or one hundred eighty days. Buying early enough, often within two to three weeks of the first deposit, can switch that exclusion off, which makes the purchase date as important as the price.
Cruise and ship-specific clauses
Standard policies stop at the shore. Look for missed connection cover that pays when a delayed flight makes you miss the sailing, port change or itinerary change benefits, and whether evacuation from a ship counts under the medical section. These are the claims cruisers actually make.
What the credit card already gives you
Premium cards carry trip delay and baggage benefits that are genuinely useful and often forgotten. I check them first, then buy only the gaps, since paying twice for identical cover is the commonest waste in this category.
The excess and the claim route
An excess of two hundred fifty dollars on a five hundred dollar cancellation turns a claim into a decision people avoid. Alongside it, I look at how a claim is filed: an online form with a named contact beats a phone number that only opens in office hours.
Who underwrites the policy
The brand on the comparison site is rarely the insurer behind it. The underwriter is printed in the policy wording, and its financial standing decides whether your claim is paid in a bad year for the industry, which is exactly the year you need it.
What I do not buy
Two items get cut from almost every policy I review. Rental car excess cover is usually cheaper bought at the counter or already held by a card, and the flight-only delay cover is worth little when the airline owes you the same money under its own rules. Cancel-for-any-reason add-ons are the third: they cost a fifth of the premium and pay a fraction of the claim, so I take them only on trips with a real chance of backing out, such as a group week where one family's situation can change the whole booking.
How a claim actually runs
Claims fail on records rather than on reasons, so I keep one folder per trip with the same four things in it from the day the deposit goes out. The folder sits in one place that both I and the client can open, and nothing waits until the end of the trip, when dates and amounts have gone soft in memory.
- The policy wording and the schedule of cover, saved as a file rather than a link.
- Every supplier confirmation, with the dates and the amounts that would be lost.
- Anything that supports a claim later: a doctor's note, an airline delay message, a photo of a closed port.
- The receipt trail, because the payout is matched against what you paid, not against what you were quoted.
Notification windows are short, often forty-eight to seventy-two hours from the event, so the insurer is told early and the paperwork follows. I file the delay message from the airline the same day rather than at the end of the trip, since reconstructing two weeks of receipts in a hurry is where otherwise valid claims stall.
When I buy it
As soon as the first non-refundable payment leaves the account, which ties the cover to the deposits as well as the balances. Waiting until the final balance means paying a higher premium on a trip that is already at risk. For a sailing I check the line's own cancellation schedule against the wording, because the two have to agree before a claim covers what the deposit actually was. Those decisions sit alongside the cabin and fare choice, since the refundable fare and the policy often solve the same problem twice.