evidence: The Gibraltar-Spain border is a busy external Schengen border and Gibraltar is outside the Customs Union. [...] If you are crossing the land border from Gibraltar into Spain, read Spain travel advice for the latest entry requirements, particularly the evidence you may need to show at border control. Some travellers have not been able to provide the full documentation asked of them and have had their travel plans disrupted. [...] Gibraltar is not part of the EU Customs Union. If you travel from Gibraltar to Spain, declare any duty-free goods to Spanish customs officers.