Although Bulgaria's telephone system has greatly improved in recent years, it remains patchy. Because investment has been concentrated on business communications, international and trunk calls are often easier than local ones, especially using the new public telephones taking phonecards ( fonkarta ). These can usually be found in post offices, hotel lobbies and major public buildings such as cultural centres and concert halls. There are two systems, using separate phones and non-interchangeable cards, Bulfon (whose phones are orange) and Betkom (with blue phones). It's best to carry both cards as you never know which system will be available (in some towns one has a monopoly). You can use them to make any kind of direct-dial call for the same cost as you'd pay in a telephone office or private house. Phonecards are sold at post offices and many shops and kiosks.

In the absence of a cardphone you'll have to fall back on the telephone offices ( telefon ) attached to post offices, where you are assigned a cabin and pay for your call afterwards. The telephone section is usually open longer than other parts of the post office, often as late as 11pm in major cities and 24 hours in Sofia. As most hotels levy extortionate surcharges on international calls , you'll almost always save money by going through a phone office instead. Note that Bulgaria is one of the few countries in Europe with no peak or off-peak rates , so you can call at any time without worrying about extra costs.

Domestic calls can be fraught with difficulties in rural areas, where getting a connection between the main town and a village may necessitate going through the telephone office, as direct-dialling isn't possible. Another peculiarity is that within such regions, the phone codes for settlements differ from those used when calling long distance or from abroad. For example, the national code for Melnik is 07437, but within the Pirin region its prefix is 997437. If you can't get though using the prefix starting with 0, try using 99 instead. In this guide, all codes are given in the zero-form, unless they only work as 99 calls.

GSM mobile phones can be used almost everywhere in Bulgaria save for mountain valleys, although you should contact your network to ensure that your international roaming facility is activated (often entailing the payment of a hefty deposit) before you travel.