A car that a household uses for ordinary errands is one kind of risk. A car that is driven for pay, carrying passengers or deliveries for many hours each week, is a different kind of risk, and the contract may treat it differently. Before you buy, find out how the provider classifies the way the car is used, because the classification can decide whether a claim is accepted at all.
Find the use clause
Look for a section that describes personal use, commercial use, or livery use. Read what counts as each. Some contracts define commercial use by the way the car is registered or insured, while others look at what the driver reports at signing or at claim time. Ask which test applies, and ask whether a change in use during the term must be reported.
Check the mileage
Paid driving tends to add miles quickly. Compare the car's expected yearly miles with the mileage limits in the contract, and find out what happens if the odometer reaches the limit early. Some providers take higher-mileage cars than others, so the list of providers that take high-mileage cars is worth a look before you narrow the field.
Ask what happens after a change
If you start paid driving after the contract begins, ask whether the provider must be told, how quickly, and in what form. Ask whether the contract can be voided for an undisclosed change in use, and whether that voiding would reach back to repairs already paid. Get the answer in writing, and keep the reply with the contract.
Keep the other coverage in view
A service contract is not a substitute for an insurance policy, and paid driving usually brings its own insurance questions. Talk with the car insurer about how the vehicle is classified, and check any platform's own requirements for the vehicle. Those questions sit outside the contract, and the contract may not answer them for you.