Area codes in Belgium are, excluding the leading '0', one or two digits long. Numbers are of variable length; landlines have a seven-digit subscriber number and a one-digit area code, while smaller cities have a six-digit subscriber number and a two-digit area code. All Belgian telephone numbers dialled within Belgium must use the leading '0' trunk code. Area codes are separated from the subscriber number by a slash and a space, and subscriber number digits are either in the format xxx xx xx , xx xx xx , or xxx xxx . Belgium 0x xxx xx xx - dialling a bigger city, such as Brussels, Antwerp, or Liège 0xx xx xx xx - dialling a smaller city, such as Ypres or Mons 04xx xx xx xx - dialling a mobile number from a landline or another mobile phone. From outside Belgium, a caller would dial their international call prefix (typically 00 in Europe and 011 in North America), followed by 32 (the country code for Belgium), then the area code minus the trunk code '0', and finally the local number. Dialling from New York to Brussels 011-32-2-555-12-12 - Omitting the leading "0". Dialling from New York to Charleroi 011-32-71-123-456 - The subscriber number shortens with the addition of a number to the area code. Dialling from New York to a mobile number 011-32-4 x x-12-34-56 - The dialler omits the leading "0". Mobile/GSM area codes always begin with 04xx and the subscriber number is six digits long. Numbers are usually provided by Mobistar, Base, or Proximus. Each provider has a unique number assigned as the second digit in the area code: Proximus numbers begin with 047x , Base numbers with 048x and Mobistar numbers with 049x . With the introduction of number portability, area codes may no longer correspond with their providers.