UK(GOVT OF) 0% T-BILL 25/09/2023 GBP – BP20TY9 GB00BP20TY91
For government issued securities, the only necessary criteria that has to meet for the securities to be ISA qualifying is that they are issued by (or on behalf of) a government in the European Economic Area (EEA) including the UK. So, all UK Gilts (Gilt Edged Securities) and UK Treasury Bills (like this one) are stocks & shares ISA qualifying (despite not finding anything with the ISIN/SEDOL/Name, for this UK treasury bill).