Most buyers treat service history as a checkbox. That’s a pricing mistake.

When a mechanical watch goes in for a full service, here's what actually happens:
The movement is completely disassembled, often 200+ individual components. Every part is cleaned in an ultrasonic bath to strip oils, debris, and oxidation. A trained watchmaker inspects each component under magnification, checking for wear on jewels, pivots, and the escapement. Parts that don't meet tolerance are replaced.

Then the movement is reassembled with fresh lubricants applied in precise quantities to specific contact points. Too much is as damaging as too little. The watch is placed on a timegrapher across six positions to regulate timing deviation. On a high-grade movement, the target is under five seconds per day.

The case is refinished, either polished on brushed surfaces or bead-blasted on matte ones. On anything with a water resistance rating, the gaskets are replaced and the case is pressure tested before it leaves the bench.
A full service on a complicated movement at an authorized service center typically runs $1,200 to $4,000 depending on brand and complexity. That matters on a $25,000 watch.

What buyers should ask for: the service invoice, not just the verbal assurance. Who performed it, when, and what was replaced. Brand-authorized versus independent matters. A watch serviced two years ago with documentation is worth more than one serviced three months ago without it.

Service history is a pricing variable. Treat it like one.