While most apostille requests follow a straightforward process, some situations involve special circumstances or edge cases. Understanding these scenarios can help avoid delays when preparing UK documents for use in Spain.

UK nationals who were born outside the UK (for example, in a former colony, or to expatriate parents) may have birth certificates that were issued by a foreign country rather than by a UK authority. In this case:

• The birth certificate from the foreign country needs to be apostilled by that country's competent authority, not the UK FCDO
• If the birth was registered with the UK Consulate, a consular birth registration certificate can be obtained from the FCDO, which can then be apostilled
• Some UK nationals may have both a foreign birth certificate and a UK registration the UK registration document can be apostilled

British citizens who were naturalised from another country may have documentation that spans multiple countries. Their UK naturalisation certificate (or certificate of registration as a British citizen) can be apostilled by the FCDO. This document may be useful in Spain to prove their British citizenship if other evidence is unclear.

People with both UK and Spanish nationality are in an interesting position. For Spanish purposes, they are Spanish citizens and would normally use their Spanish documents. However, if they have UK-issued documents that are relevant (for example, a marriage that took place in the UK), those documents may need apostilling just as for any other UK national.

Documents for children often involve apostilles birth certificates for children born in the UK to parents moving to Spain, school records, or other documents. The apostille process is the same regardless of whether the subject is an adult or a minor. However, some Spanish processes involving minors (such as school enrollment or healthcare registration) may have specific requirements beyond the apostille.

Occasionally, people need to apostille historical documents for example, to establish genealogy for Spanish citizenship applications based on grandparental descent (the democratic memory law), or for inheritance claims involving older estates.

Historical civil registration documents can generally be ordered from the GRO or other registries as certified copies bearing current official signatures, which can then be apostilled. The FCDO has historical records of signatories and should generally be able to apostille documents with older signatures where the signatory's details are on their register.

The Channel Islands (Jersey and Guernsey) and the Isle of Man are Crown Dependencies they are not part of the United Kingdom. Their documents are not apostilled by the FCDO. Each has its own competent authority for apostilles under the Hague Convention. If you have documents from Jersey, Guernsey, or the Isle of Man that need to be used in Spain, you need to obtain apostilles from the relevant Crown Dependency authority.

Documents from British Overseas Territories (such as Gibraltar, the Cayman Islands, or Bermuda) are also not apostilled by the FCDO. Each territory has its own apostille arrangements. Gibraltar is a special case because it is geographically part of the Iberian Peninsula and has specific arrangements with Spain.

If an apostilled document you have submitted to a Spanish authority is lost or mishandled, you may need to obtain and apostille a replacement. Unfortunately, apostilles cannot simply be reissued each apostille is tied to a specific physical document. If the document has been lost, you will need to obtain a new original or certified copy and go through the apostille process again. This underlines the importance of keeping copies of everything and using tracked delivery.

If you receive back an apostilled document and notice an error in the apostille certificate itself (such as an incorrect date or name spelling), contact the FCDO as soon as possible. Errors in the underlying document are more complex the apostille cannot be transferred to a corrected document; you would need a corrected document to be reissued and then separately apostilled.