The use of carrier selection codes can be very confusing, because of the obvious added complexity, the different rates charged by different carriers, and even which long-distance carriers can be to place the call, since not all of them service the entire Brazilian territory, and some are only available from mobile or from VoIP lines. For example, Embratel (selection code 21 ) is available from any telephone line in all of Brazil, but Sercomtel (code 43 ) only in the cities of Londrina and Tamarana (and some neighbouring cities).ANATEL's had a useful on-line system (in Portuguese) where the standard rates of all available carriers could be compared for the particular long-distance call one wants to place, but it was cancelled by 2013 March.