Numbering examples for Lisbon area:[REF] .
xxx xxxx (before 1999, within Lisbon) 01 xxx xxxx (before 1999, within Portugal, including Lisbon) +351 1 xxx xxxx (before 1999, outside Portugal) 21 xxx xxxx (after 1999, within Portugal, including Lisbon) +351 21 xxx xxxx (after 1999, outside Portugal) +351 xx xxx xxxx (present day) .