Identify a Patek Philippe: Reference and Model Guide

Patek Philippe gives every watch two numbers in addition to its reference: a case number and a movement number. Where they appear depends on the caseback.

• Display caseback. On modern watches with a sapphire back, such as the Nautilus and Aquanaut, the reference and case number are engraved on the metal ring around the crystal; the movement number is on the calibre, visible through the glass.
• Solid caseback. On classic Calatravas and vintage pieces the numbers are engraved inside the back, so a watchmaker must open the watch. The 5227's hinged dust cover over a sapphire back is the exception.
• Papers. The Certificate of Origin lists the reference, case number and movement number. For older watches, Patek Philippe sells an Extract from the Archives that confirms all three along with the production and sale dates.

Patek Philippe does not engrave the reference between the lugs the way Rolex does. A reference engraved there is a warning sign; read our guide on how to spot a fake luxury watch.

A full modern reference such as 5711/1A-010 has up to four parts, and each one tells you something.

Part	Example	Meaning
Model number	5711	Four digits identifying the model. 5xxx and 6xxx are current men's references, 7xxx are ladies', 3xxx are earlier generations and 4xxx were mostly ladies' models
Bracelet marker	/1	Indicates an integrated metal bracelet rather than a strap. 5711/1A is on a bracelet; 5167A is on a strap
Material letter	A	A is steel (acier), R rose gold, G white gold, J yellow gold, P platinum. T appears on rare titanium pieces
Dial code	-010	Three digits distinguishing dial colours and variants of the same reference. 5711/1A-010 is blue, 5711/1A-011 is white

Vintage references are shorter: the 96 is the original 1932 Calatrava, the 2499 and 1518 are the famous perpetual calendar chronographs, and the 3700/1A is the first Nautilus from 1976. Older references often omit the material letter, so a 2499 might be yellow, rose or white gold; the papers or case engraving settle it. For other houses, see watch reference numbers explained.

Patek Philippe does not publish serial-to-year tables, and the case and movement numbers follow separate sequences per calibre and case type. Dating a Patek Philippe therefore works differently from dating a Rolex or Omega.

• Modern watches. The Certificate of Origin shows the sale date. Production usually precedes it by months rather than years.
• Older watches. The Extract from the Archives, issued by Patek Philippe from its own records, gives the production year and sale date; collectors treat it as a basic requirement for a vintage purchase.
• Reference era. The reference gives a rough period: three-digit and low four-digit references date from before the 1960s, 3xxx references from the 1960s to the 1990s, and 5xxx references from the 1990s onward. Some stayed in production for decades, so this only brackets the earliest possible date.

The case and movement numbers on the watch must match the certificate or extract; mismatched or re-engraved numbers are a common sign of a franken-watch or a fake. Number ranges published online are collector estimates and should be read as such.

• Nautilus: porthole case with rounded octagonal bezel and ears at 3 and 9 o'clock, horizontally embossed dial, integrated bracelet. The 5711 is time and date, the 5712 adds small seconds, moon phase and power reserve, the 5726 is an annual calendar.
• Aquanaut: rounded octagonal case without ears, embossed grid dial with Arabic numerals, matching composite strap. The 5167A is the 40.8 mm steel model.
• Calatrava: round dress watch. The 6119 has a hobnail Clous de Paris bezel, the 5227 a plain bezel and hinged caseback cover, the 5196 small seconds at 6 o'clock.
• Complications: annual calendars such as the 5146 (moon phase and power reserve) and 5205 (three apertures at 12 o'clock); annual calendar chronographs such as the 5960.
• Grand Complications: perpetual calendars, perpetual calendar chronographs such as the 5270, minute repeaters and split-seconds chronographs.
• Golden Ellipse: elliptical case, often with a blue sunburst dial.
• Gondolo: rectangular or tonneau Art Deco cases.

The Calatrava cross on the crown and the Geneve signature appear on all lines and do not separate them.

• Nautilus vs Aquanaut. The Aquanaut has no ears, a grid dial with numerals and a composite strap. The Nautilus has ears, horizontal grooves and usually a bracelet.
• 5711 vs 5712 vs 5726. Clean dial with date at 3 o'clock is the 5711; off-centre small seconds with moon phase is the 5712; day, date and month apertures with moon phase is the 5726.
• 5711 vs 3700 vs 5800. The 3700 is the vintage Jumbo with no seconds hand, the 5800 the smaller mid-size reference, the 5711 the 40 mm model with central seconds.
• Nautilus vs Royal Oak. Both are Gerald Genta designs. The Royal Oak has a sharp octagonal bezel with eight screws; the Nautilus bezel is rounded with none. See our Audemars Piguet identification page.
• Integrated-bracelet sports watches. Many brands make steel sports watches on integrated bracelets. Ears on the case and a grooved dial are Nautilus features; octagonal screws and a tapisserie dial are not.

The Nautilus and Aquanaut are heavily counterfeited, so a visual match is never enough on its own.

Patek Philippe dials carry little text, so the case and the complication layout do most of the work.

1. Shoot the dial straight on in soft light so the embossed pattern, hands and any sub-dials are visible. Avoid reflections that hide the signature.
2. Include the case sides and the bracelet or strap. Bracelet versus strap and the ear shape on a Nautilus are reference-level details.
3. If the watch has a display back, photograph it. The calibre layout and any visible engraving narrow the reference quickly.

WatchID compares the image against a reference database and returns ranked candidates with model names and references. For a blue Nautilus on a bracelet it will typically propose the 5711/1A-010 alongside the 5712/1A, which shares the case and bracelet and differs in dial layout.

A photo result is an identification, not a judgement of authenticity. Confirm the reference against the caseback engraving and the Certificate of Origin, and read how to identify a watch from a photo for the general method. For a comparison with Rolex, see our Rolex identification page.