I give it a couple of months before the first story hits about a government department cock up leading to the Inland Revenue taking someone who is dead to court because they havent paid their taxes.
Oh they've done that quite a few times.
Just my own experience:
Southampton City Council were still trying to take my father to court alleging unpaid council tax two years after we had told them of his death and two years after his widow (my mother obviously) had moved to Dorset.
After Mum died the Revenue started to pursue my dead father over his failure to send in a tax return from beyond the grave. They kept applying "fines" for his tardiness in failing to file a return and/or make any payments.
I got them to stop only after lengthy arguments and by inviting them to "dig him up" for their proposed court action.
Production of Death Certificates for both parents made no difference to them. I did actually get one letter that read "Dear Mr Deceased".