As a result of Bulgaria's EU accession, I contacted the Bulgarian Embassy in London to ascertain whether Police Registration was still required when staying at our properties.
The following is the reply which I have received:
Please note that holders of valid ordinary passports and ID card issued from one of the EU countries (including UK (British Citizen Passport Holders only) do not need a visa to visit Bulgaria and stay there for 90 days each time. During this time visitors do not need to register at a police station. However, British Citizen Passport Holders and other EU citizens, who wish to stay longer and live in the country, should within the space of the initial 90 days stay apply for a Bulgarian ID card and permition to reside in there at the local Police Station at their address in Bulgaria.
Kind regards,
Visa Section