Singapore phone number: eight digits opening on a 3, 6, 8 or 9, with the +65 country code optional. Singapore has no trunk prefix and no area codes, so the opening digit is the only thing that says which kind of line it is.
Label: SG_PHONE
(?<![\w+])(?:\+65[\s.-]?)?[3689](?:[\s.-]?\d){7}(?!\w)(?![\s.-]?\d)Call +65 6123 4567 for the front desk. → +65 6123 4567My handphone is 9123 4567 if you need me. → 9123 4567The room number is 1123 4567Extension 6123Tags: sg, contact