How to check a watch has genuinely been serviced

To check if a watch has been serviced, ask for the service invoice or the brand’s service card, check that the serial number and dates on it match the watch, and confirm with the service centre that the job is on its records. Then have a watchmaker time the watch and pressure test it. A seller’s word that a watch “has been serviced” is not evidence; paperwork and test results are.

A service is the strip-down, cleaning, lubrication and regulation of a watch’s movement, with new seals and a water resistance test. Prices and intervals by brand are in our guide to UK watch servicing costs.

How do you check if a watch has been serviced?

Look for three things: a document from whoever did the work, a match between that document and the watch, and a test result that fits a recent service. Any one of them alone is weak. Together they are as close to proof as a buyer can get without opening the watch.

1. Ask for the invoice or service card, and a clear photo of it before you travel or pay.
2. Check the serial or case number, the date and the work listed.
3. Contact the service centre named on it, give the serial number and ask whether it serviced the watch on that date.
4. Have the watch timed on a timing machine and pressure tested.
5. Keep copies of everything with the watch’s other papers; see what “full set” means.

What service papers should a serviced watch have?

Usually an itemised invoice from the service centre or watchmaker, and for some brands a service card or guarantee card. The invoice should name the business, the date, the watch’s reference and serial number, the work done and any parts replaced. A brand’s service card shows the guarantee on the work.

Some brands issue a card after a full service. Tudor says that after every full service by an Official Tudor Retailer or Service Centre, the watch comes back with a Tudor Service Card carrying an international two-year guarantee (Tudor, 2026). Rolex gives a two-year Service Guarantee after a complete service (Michael Spiers, a Rolex retailer and service centre, 2026). Omega and TAG Heuer each give 24 months on their service work (Omega, 2026; TAG Heuer, 2026).

So the date on a guarantee tells you something: if a card shows the guarantee has a year left, the service was about a year ago. Ask to see the card itself rather than a description of it.

Does a purchase warranty mean the same as a service guarantee?

No, and mixing the two up is an easy mistake when a seller quotes an impressive-sounding number. A purchase warranty covers the watch from the point it was first sold, for defects in manufacture; a service guarantee covers only the specific work a service centre has just done, starting from when that work finished. Some of the industry’s longest-running warranty figures are purchase warranties, not service guarantees, and knowing which one you are being told about changes what a given date actually proves.

Jaeger-LeCoultre, for instance, introduced an eight-year warranty on new watches in spring 2019 through its JLC Care programme, requiring online registration, and the specialist title WatchesBySJX described it at launch as the longest guarantee period among major watch brands (WatchesBySJX, “Jaeger-LeCoultre Announces 8-Year Warranty for All Watches”, 6 May 2019, checked 29 October 2026). Cartier introduced a similarly long eight-year purchase warranty under its Cartier Care programme around the same period. Neither of those figures is a service guarantee: they describe how long the brand backs the watch from new, not how long a particular repair is guaranteed for. IWC’s International Service Guarantee, by contrast, is explicitly a post-service guarantee, running 24 months from when the watch is returned after a Restoration or Complete Service, or 12 months after any other kind of service, and IWC says it covers defects in spare parts and workmanship on that specific repair, is void if the watch is serviced anywhere other than an authorised IWC service centre, and does not cover ordinary wear and tear, misuse, or routine maintenance (IWC, International Service Guarantee, checked 29 October 2026).

Sources: WatchesBySJX, "Jaeger-LeCoultre Announces 8-Year Warranty for All Watches"; IWC, International Service Guarantee. Checked 29 October 2026.

The practical point: when a seller mentions a warranty or guarantee figure, ask directly whether it is the original purchase warranty or a guarantee on a specific piece of service work, and ask for the dated document either way. Only the second kind tells you anything useful about when the watch was last actually serviced.

How can you check a service invoice is genuine?

Ask the business that issued it. Give the serial number and the invoice date, and ask whether its records show the job. Brands can trace this: Audemars Piguet, for example, says it uses a watch’s case and movement numbers to trace its service history (Audemars Piguet FAQ, 2026). An independent watchmaker can confirm its own work too.

Also check that the business is who it says it is. Patek Philippe says its watches must be serviced only by authorised retailers or authorised service centres, and its site has a page to find them (Patek Philippe FAQ, 2026). Most brands have a “find a service centre” page; use it. For an independent, the British Horological Institute keeps a register of accredited repairers whose listed members have met its requirements for accredited qualifications (BHI, 2026). A watchmaker who is not on that register may still be good, but you can check one who is.

What can a watchmaker tell about a watch’s service?

A good deal, without a full strip-down. A timing machine shows how the movement is running; a pressure test shows whether the seals hold; and with the caseback off, the watchmaker can see the state of the movement and gaskets. None of these proves the date of a service. They show whether the watch behaves like one recently serviced.

Timing. A timegrapher is a machine that listens to the ticks of a mechanical watch to measure its accuracy (Wikipedia). Witschi, a maker of these machines, lists the three main readings as rate deviation, amplitude and beat error (Witschi). Rate is the gain or loss in seconds a day. Amplitude is how far the balance wheel swings, in degrees. Beat error is how unevenly it swings either way. A watchmaker reads them in several positions, as COSC does when it tests a new chronometer in five positions over several days (COSC, 2026). For a reference point, COSC’s limit for a new mechanical chronometer is an average of −4 to +6 seconds a day; see what COSC certification means. A pre-owned watch is not held to that, but a watch said to be fresh from a service that runs far off it, or with a low, falling amplitude, needs explaining.

Water resistance. A pressure test checks the case against its rating. Seals age: Seiko’s UK pages say water resistance is not permanently guaranteed and is affected by ageing gaskets and by knocks (Seiko UK, 2026). A full service normally includes new gaskets; Omega’s complete service lists replacing the components that ensure water resistance (Omega, 2026). A watch said to be recently serviced should pass. More in what water resistance ratings mean.

Inside the case. With the caseback open, a watchmaker can look for clean, lubricated parts, fresh gaskets, scratches from tools, and dust or old oil. Only let a qualified watchmaker open a watch, and ask the seller’s permission first.

Some brands offer a check without a full service. Cartier’s free functional check tests precision, water resistance and, on mechanical watches, magnetisation (Cartier UK, 2026).

What should you ask the seller?

Ask direct questions and ask for the answers in writing. Who serviced the watch, and when? Was it a full service or a partial one? Which parts were replaced, and do you have the old ones? Was the case polished? Has it been worn in water since? Can I contact the service centre to confirm?

Then ask about the original parts. A service can replace the dial, hands, bezel insert or crown, and some buyers care about that. If the invoice lists them, ask whether the originals come with the watch. Polishing during a service changes the case; see how to tell if a watch has been polished. Our list of questions for a used watch seller covers the rest of the conversation.

A worked, illustrative example shows why this conversation is worth having before you agree a price, not after. Say a seller is asking £5,000 for a watch with no service papers at all, and a main dealer or independent watchmaker quotes, as an example figure only, around £450 for a full service on that model. If you factor that cost into your offer and the seller will not move, you are effectively paying full price now for a service you will also have to pay for later; if the seller instead reduces the price by roughly that service cost, or has the service done and shows you the invoice before completing the sale, the deal looks very different even though the watch itself has not changed. Either way, raise the missing service history as a reason for your offer, in writing, rather than discovering it only after you have paid.

Does an unworn or “new old stock” watch need checking too?

Yes, for a different reason. “New old stock,” often shortened to NOS, describes a watch that has never been worn but was manufactured some years ago and has sat unsold, in its box, since then. Because it has never been on a wrist, a seller will sometimes imply it needs no service at all, but the lubricants inside a mechanical movement age with time whether or not the watch has ever run, and seals can age sitting in a box in the same way they age on a wrist. A watch presented as NOS is not automatically in better mechanical condition than a worn watch with a documented recent service; it is simply unworn, which is a cosmetic and collector’s distinction more than a mechanical one.

Ask the same questions you would of any pre-owned watch: has it ever been serviced, and if the answer is no because it has never been worn, ask instead when it was manufactured and how long it has been stored, and treat a long storage period as a reason to budget for a first service soon after buying, not as a reason to skip checking it. A timing test and pressure test before you rely on the watch day to day apply just as much to an unworn watch as to a worn one.

What about an auction lot with unclear service history?

Auction catalogue descriptions vary widely in how much service detail they give, and a condition report that says nothing about servicing is not the same as a watch having none; it may simply mean the house does not have that information, or has chosen not to print it. Email the specialist department before you bid and ask directly whether the consignor supplied any service papers, and if none exist, ask whether the house’s own condition report included a functional check and what it found. Get the answer in writing or keep the email, since a verbal assurance from a call is harder to rely on later than a written response you can quote back if a dispute arises.

Because bids are binding and, for a public auction you could attend, the usual 30-day right to reject does not apply to second-hand goods, as our buying a vintage watch guide explains, budgeting for an unknown service history is the safer assumption at auction specifically, more so than with a dealer who may offer a return. Price your maximum bid as if the watch will need a service soon, and treat any papers that do turn up as a pleasant surplus rather than something to rely on sight unseen.

Signs of a recent service vs signs of neglect

Checking a watch yourself before a watchmaker does gives you a sense of what you’re dealing with. None of these is proof on its own, but they point the same way as the paperwork and the test results above.

Based on what a watch behaves like after the servicing steps described by Omega, Breitling and Seiko above (case and crown sealing, lubrication, timing), not a brand-specific checklist. A watch can still need professional testing even if it feels fine; use this alongside a timing machine and pressure test, not instead of them.

What are the red flags?

• “Recently serviced” with no invoice, card or name of the service centre.
• An invoice with no serial number, or one that does not match the watch.
• A service centre you cannot find, or that is not on the brand’s list.
• A guarantee card with dates that do not fit the seller’s story.
• An invoice listing only a battery or a pressure test, described as “a full service”.
• A seller who will not let you contact the service centre.
• A watch that runs badly or fails a pressure test soon after a claimed service.

One more: a service by someone the brand does not authorise can affect the brand’s warranty or service guarantee. Rolex’s Service Guarantee is voided by work from a non-Rolex-authorised third party (Michael Spiers, 2026), and Omega’s service warranty is void if anyone not approved by Omega SA works on the watch (Omega, 2026).

Frequently asked questions

Can I check a watch’s service history with the brand?

Often, with the serial number. Audemars Piguet, for example, says it traces service history by case and movement number. Ask the brand’s customer service.

What is a service card?

A card some brands give after a full service, showing the guarantee on the work. Tudor’s Service Card carries a two-year international guarantee.

Does a service invoice prove a watch is genuine?

No. It shows that a business worked on a watch with that serial number. Check the invoice with the business that issued it.

Can a watchmaker tell when a watch was last serviced?

Not the date. A timing test, pressure test and look inside show whether the watch is in the state you would expect after a service.

What does a timegrapher measure?

Rate in seconds a day, the balance wheel’s amplitude in degrees, and beat error. These show how well the movement is running.

Should I pay for a check before buying?

If the watch is valuable and the service claim matters to the price, a timing and pressure test is a small cost. Agree it with the seller first.

Is a partial service the same as a full service?

No. A partial service usually renews seals and cleans the case without overhauling the movement. The invoice should say which was done.

What if the seller has no papers at all?

Treat the watch as unserviced. Budget for a service, and see our guide to servicing costs for brand prices.

Do independent watchmakers give service papers?

Good ones give an itemised invoice and a guarantee. Ask before you book.

Is an 8-year watch warranty the same as a service guarantee?

No. Figures like Jaeger-LeCoultre’s and Cartier’s eight-year warranties are purchase warranties that run from when the watch was new, not guarantees on a specific service. A service guarantee, such as IWC’s 24-month cover after a complete service, starts from when that particular repair was finished and tells you something useful about dating the work.

Does a “new old stock” watch need a service check?

Yes. It has never been worn, but its lubricants and seals age with time in storage much as they do on a wrist. Ask when it was manufactured and how long it has been stored, and budget for a first service as you would for any watch with no service history.

How should I treat an auction lot with no stated service history?

Assume it may need a service soon and price your bid accordingly. Email the specialist department beforehand to ask what the consignor supplied and what the house’s own condition report checked, and get the answer in writing where you can.

We check the facts in this guide against the sources named, and it is correct to the best of our knowledge as of October 2026. Rules, rates and sellers' terms change, so confirm the details with the seller, or with a professional, before you buy.