Patek PhilippeNautilus 5990/1A

Before you buy a used Nautilus 5990/1A

• Prefer the Authenticity Guarantee. On eBay UK most watches over £1,500 are checked by an independent authenticator before they're sent to you. Look for the green tag on the listings above, or tick "Authenticity Guarantee" in the filters.
• Check the reference and serial. Ask for a photo of the reference and serial on the case back, and make sure they match the papers. The reference should be 5990/1A.
• Box and papers should match the watch. The serial on the warranty card must match the case. A "full set" with a generic box or papers from another watch is worth no more than the watch alone.
• Be wary of a price far below typical. Most fakes and scams are priced 30–50% under the going rate to look like a bargain. We flag anything 35%+ under similar listings and never count it as a deal.
• Ask about servicing. A full service costs £700–£1,500 at the brand, so a recent service with paperwork adds real value. Ask when it was last serviced and whether it keeps time.
• Look for polishing and replaced parts. Sharp case edges and unpolished lugs add value; aftermarket dials, bezels or diamonds take it away. We remove listings that say "custom" or "aftermarket", but check the photos.
• Pay through eBay. eBay's Money Back Guarantee only covers you if you pay through eBay. Never pay by bank transfer outside it, however good the deal. Our fake watch checklist has more.