Thanks for your concern,
Vietnam offers 15-day visa exemptions with single entry for visitors from the U.K.. However, their
passports should have at least six months of validity and their arrival date is NOT within 30 days from their last exit date with visa exemption.
Otherwise, they will need a Vietnam visa.
If you stay more than 15 days please apply for Vietnam visa.
For any further details, please contact us at firstname.lastname@example.org or call us at +84.327.117.119
Stepfano Tran (Mr.)