Your EPIRBs or PLBs should be registered in the country where you live, or where your vessel is registered. The links below are intended to help you find where to register your devices.
For the UK: UK Beacon registry
For the USA: NOAA Sarsat
For Australia: AMSA
For New Zealand: NZ Beacon registry
For Canada: Canadian Beacon Registry
For other countries, please use the country list provided by Cospas Sarsat here.