It is theoretically possible to get an apostille for an expired enrolment letter under certain circumstances. In practice, it is rather difficult.
For instance, if you need to demonstrate that you were enrolled at a particular college, university or training establishment in the past (but are no longer enrolled there), you can get a notary public to notarise your enrolment letter for that year. The letter of enrolment bears a date of issue and states the duration of the course.
However, before the letter can be submitted to the legalisation office of the FCDO, the notary will check with the institution concerned that you attended the course at that time and will add a notarial comment to that effect.
The Competent Authority in each country issues apostilles.
In many countries, the Competent Authority certifies only that the signatures, stamps or seals match their own records. Thus, in the UK, the FCDO holds records of approved notaries and solicitors together with their stamps, seals and sample signatures.
Moreover, in the case of academic and professional qualifications, the UK’s legalisation office will also “… verify the validity of the issuing institution against a list of recognised institutions before issuing an apostille relating to the notarial certification”.
The FCDO, therefore, consults a number of different government, academic, training and professional registers to ensure that your letter of enrolment comes from an accredited source .
These measures exclude bogus qualifications, but they also help you get an apostille for a letter of enrolment that has expired – provided it comes from a legitimate source.