When a claim turns on what was done to the car and when, the paper you can show matters as much as the paper the shop wrote. Before you sign, decide who keeps the service file, because the contract may ask for proof you have not thought about yet.
What the contract may ask you to show
Many vehicle service contracts require routine maintenance to be done and recorded. The paperwork may need to show the date, the odometer reading at the time, the work performed, and who performed it. Some contracts accept a receipt from any shop. Others want a licensed facility, a dealer, or a particular type of record. The wording differs, so the only safe way to know is to read the maintenance clause and any records section in the contract you are about to sign.
Your file or the shop invoice
A shop invoice is often the strongest single record, but it is not always complete. Some invoices leave out the mileage. Some list a part without the work order. Some come from a shop that later closes. Keeping your own file means saving every receipt, the work order, and any digital copy, then writing the mileage in a notebook or phone note on the day of service. You are not replacing the shop's paper. You are backing it up.
Questions to ask before you sign
Ask the seller or the provider what records they require for maintenance and for any claim that touches maintenance. Ask whether a receipt needs the odometer reading, whether a photo of the invoice counts, and whether an electronic record is accepted. Ask how long you need to keep the file, because the contract term may run longer than you expect. Ask what happens if the shop that did the work is no longer in business. Get the answers in writing, and check them against the contract language itself, not against the sales conversation.
A practical habit
Create one folder, physical or digital, the day the contract starts. Put the signed contract, the maintenance schedule the contract references, and each service invoice inside it. Add the odometer reading to each invoice. When a claim comes up, the file should answer three questions without a search: what was done, when, and by whom. If you cannot answer those from your own folder, a denial can be harder to contest, however reasonable the repair was.
For a plain explanation of how this site reads contract terms, see How We Score Vehicle Service Contract Companies. The paper trail is the part of the contract only you control day to day, so start it on day one.