Can a United Kingdom citizen travel to Guernsey?

No visa required for entry to Guernsey. Stays of up to 90 days are permitted under the visa-waiver agreement.

You're travelling to Guernsey (GG). Your home cellular plan may or may not include data abroad — check your carrier's international options before you fly. An eSIM is a low-commitment alternative if your plan doesn't cover the destination or charges high roaming rates.

Declare GBP 10,000 or equivalent when entering or leaving United Kingdom (GB). Form: HMRC declaration. Declare £10,000+ in cash when traveling to/from UK

Your GB citizenship lets you travel freely across the Common Travel Area - Ireland, the United Kingdom, and the Crown Dependencies of the Isle of Man, Jersey, and Guernsey - with no visa, residence permit, or onward ticket; British and Irish citizens face no routine immigration control on CTA-internal routes (you may still be asked to prove identity and nationality). The reciprocal right to reside, work, and study without a permit applies between the UK and Ireland. The Crown Dependencies run their OWN housing and work controls - Jersey's Control of Housing and Work Law, the Isle of Man work-permit regime, and Guernsey's Population Management Law - so you can visit freely, but living or working there can require a permit or qualifying status even for a British or Irish citizen. The CTA pre-dates EU membership and is unaffected by Brexit. Carry your passport.