The literal meaning of APOSTILLE AND LEGALISATION SERVICE is certification and is a French word. The apostille certificate is a result of a Hague Convention, a treaty between over 100 countries that allowed documents issued in one country to be accepted in another. For most people living in their country of birth, getting married to someone from that same country and working there too, it’s unlikely to ever come up. However, should you decide to emigrate either permanently or for a short time for work reasons, get married in another country or have a child with dual citizenship, it may be necessary to prove who you are. For example a German registrar wouldn’t know if an Irish birth certificate were the real thing as they do not have access to Irish records. In order to do this, the Foreign and Commonwealth Office qualifies that they are true UK documents prepared, stamped, signed or sealed correctly and issues the Apostille. This is a simple piece of paper that is attached to it and stamped as official. It is then signed by an official government officer.
Previous to the convention, there were no set rules and different countries had different requirements, procedures, timescales and prices for legalising documents. This caused confusion and difficulty, not to mention delays as some countries processed documents through the courts. As a solution, the convention was put into practice in 1961. Not all countries are signatories but there are mechanisms set up with the embassies and consulates of the non-attached states to allow for the documents to be used.
You may be asked to provide legalised documents, attested documents, notarised documents, certified documents. Many terms are often misused when referring to document legalisation. Ultimately, the Apostille certificate results in the document being legalised for use in another country that is a member of the Hague Convention. Certification and notarisation are often confused, especially by people in other countries where the notary system is different to that in the UK. Please always double check with the people requesting your documents before going down the notarisation route as it can get prohibitively expensive, especially when not necessary.
When a country is not a member of the Hague Convention documents are typically legalised with the apostille before then being processed by the local embassy. The embassy will then add further certification or stamps to ensure the document is valid in their own country.