It is possible to get an apostille for a degree awarded by a defunct UK university, provided the university was authorised to grant those degrees and was accredited by the UK government when the degree was awarded.
It is not possible to obtain an apostille for a degree issued by any institution that has not been properly authorised and accredited.
Established UK universities rarely close down without a trace. Instead, one university or college is often merged with another to form a new institution.
The new institution keeps the records of the former establishments.
The Higher Education Degree Database (HEDD) keeps records of degrees awarded by UK universities [2].
Polytechnics in the UK were authorised to become universities and to issue their own degrees by the Further and Higher Education Act 1992.
From 1965 until 1992, the Council for National Academic Awards (CNAA) awarded degrees from polytechnics. The records of the former CNAA are now kept and managed by the Open University (OU) [3].
All degrees, therefore, that have been appropriately authorised and accredited can still be checked, either with the awarding institution or through one of the national databases. There is usually a charge for these checks.
There are different charges depending on which agencies and institutions keep the records.