It is your responsibility to ensure that you carry the required documentation for your travel arrangements. Although British citizens do not require passports to travel to Guernsey and the Channel Islands, due to increased security, the majority of airlines now require that you produce valid photo identification at check in and they may refuse boarding if you do not do so. Documentation requirements do vary from one airline to another, but the most commonly accepted forms are a valid passport, photo driving licence or citizen card. Whilst ferry companies have not introduced this requirement as yet, it is anticipated that they may do so and if you have official photo ID, you are advised to carry it, as any carrier may ask for proof of identification at any time.