Following the break-up of Czechoslovakia in 1993, the successor states, the Czech Republic and Slovakia, continued to share the 42 country code, until 1997, with the Czech Republic adopting 420 and Slovakia adopting 421.Country Code : +420 International Call Prefix: 00 On September 22, 2002, the Czech Republic adopted a closed numbering plan, with nine-digit numbers used for local and national calls, and the dropping of the trunk code 0. Before the change, the following arrangements would have been made for calls to Brno : Local call: xx xx xx xx National call: 05/xx xx xx xx International call: +420 5 xx xx xx xx After the change, the dialing arrangements for calls to Brno were as follows: Within Czech Republic: 5xx xxx xxx Outside Czech Republic: +420 5xx xxx xxx In the case of mobile numbers, which had to be dialed in full, the only change was that the 0 was no longer used: Within Czech Republic: 602 xxx xxx Outside Czech Republic: +420 602 xxx xxx