British passports issued in Gibraltar differ from UK issued ones only in some of the wording but otherwise have the same status. The word "Gibraltar" is added beneath "United Kingdom of Great Britain and Northern Ireland" and on the information page. The only other difference is that whereas UK-issued passports state that:
Her Britannic Majesty's Secretary of State Requests and requires in the Name of Her Majesty all those whom it may concern to allow the bearer to pass freely without let or hindrance, and to afford the bearer such assistance and protection as may be necessary.
on Gibraltar-issued passports, The Governor of Gibraltar replaces Her Britannic Majesty's Secretary of State.