Check the exact place
Read the specific country or territory entry. A geographical region does not define every provider’s included zone. Offshore, aircraft and satellite connections can be treated separately from ordinary land networks.
Check the exact use
Domestic unlimited data does not establish an unlimited overseas allowance. Confirm data fair use, call destinations, duration limits and what triggers any daily arrangement. International calling from the UK is a separate topic.
Check the chosen line
On a dual-SIM phone, inspect which line supplies data and whether the other line can still incur charges. Download maps and review background activity before departure. Turning off data roaming does not prevent every possible voice or message charge.