Short answer
Verify the reference before you examine the watch. The "25894" string gets attached to a lot of Royal Oaks on the secondary market, and those watches fall into three buckets: real Royal Oaks with the wrong reference in the listing, real cases paired with a swapped dial or bracelet, and outright copies. Ask the seller for the caseback number, the movement number, and an Extract from the Archives. If those three do not line up, walk away. No set of sharp photos fixes a reference that cannot be confirmed.
Once the paperwork checks out, the tells live in the details: the octagonal bezel screws, the dial texture, the case profile, and what shows through the back. Here is the order I would work through them.
Start with the bezel screws
On a genuine Royal Oak the eight screws are functional, they hold the bezel down, and they are made of gold. The slots sit close to flush with the bezel surface and line up in a consistent pattern. Copies almost always get this wrong. Look for screw heads that sit proud of the bezel, slot angles that wander, and plating that looks soft or uneven under a phone flash. Macro shots hide nothing here, so ask for one straight down at each screw.
The dial is where copies slip
- Tapisserie texture: the grid on a real dial is stamped, so each square has depth and a slight wall. Fakes often print the pattern flat, or the squares look shallow and uneven under angled light.
- Print quality: brand text, "Automatic," and the minute track should be crisp with consistent stroke weight. Fuzzy edges or thick lettering means a reprinted or fabricated dial.
- Hands and lume: check that the handset is the correct shape for the reference, and that applied markers sit level. Printed lume is a red flag.
- Date window: the aperture should be cleanly cut with the wheel centered. A sitting date or a squinting window is common on fakes.
Measure the case, do not eyeball it
Ask the seller for a photo with calipers at the case flank and across the crystal. Royal Oaks are thin for their size, and copies are usually a millimeter or two heavy because the movement underneath is thicker. Weight matters too. Solid gold feels dense and cold; plated steel does not, though weight alone never settles it. Check the bracelet as well: link geometry, taper toward the clasp, and how the end links sit against the case. Genuine bracelets articulate smoothly with no rattle, and the clasp stamping is deep and clean rather than laser-etched and shallow.
The caseback and the movement
Engraving on the back should be deep, evenly spaced, and legible under a loupe. Shallow laser marking with the wrong font is one of the fastest tells. If the watch has a display back, look at the rotor engraving and the finishing on the bridges. Copies lean on decorated third-party movements, and the engraving on the rotor gives that away quickly. Ask for a short video with the watch running, the seconds hand sweeping, and the date flipping when advanced.
What I would ask for every time
- Caseback number, movement number, and reference, photographed in the same session.
- An Extract from the Archives or service paperwork that matches those numbers.
- Macro shots of two bezel screws, the dial from a low angle, the caseback, and the clasp.
- A video call with the watch in hand, running, before any deposit.
A plain note on the law
Selling a copy as an original is fraud, and brand owners pursue it actively. Buying a replica that is honestly sold as a replica is a different transaction with different risk, mostly around quality, warranty, and resale value. Whichever side you are on, know the difference and never pay original money for a copy.