A seller may ask for a deposit to hold a watch. Before paying, ask what the deposit reserves, whether it is refundable, and which exact watch the agreement covers. You need enough identifying information to check the piece you are being asked to buy.
A model number doesn't identify the reserved watch
Get the individual serial and compare it with a photo of the actual watch. If the seller is concerned about sharing it publicly, ask to see the serial privately or during an inspection. Don't search a number from an unrelated listing or accept a reference number in its place.
Put the deposit terms in writing
Record the seller's identity, the amount, the specific watch and serial, the hold period, and the conditions for a refund. Use a payment method that produces a receipt. Avoid a rushed transfer to a third party or a promise that the paperwork will come after you pay.
If the seller won't identify the watch
Wait. Without the serial, you cannot run an individual theft-status check or confirm that the watch later shown is the same one. A seller's refusal doesn't prove wrongdoing, but it leaves you taking a risk you can avoid by choosing another transaction.
Verify Before You Commit
Ask for the serial and written deposit terms before sending money.