Your equine may have a passport from a non-UK passport issuing organisation (PIO). This may be because you have imported the equine into the UK from another country, or you may have bought the equine from someone who originally registered the equine in another country at birth
As an owner, you must register the equine with a UK based PIO if the equine is in the UK for 30 days or longer
The UK PIO will typically "overstamp" your original non-UK passport to show that it has recognised your equine and updated the CED with its details
You can have non-UK passports overstamped by any of these UK PIOs: