However, this changed at the end of 2014 for spouses and civil partners who were allowed “additional permitted subscriptions” and in effect to inherit their late spouse’s Isa with tax benefits intact. However, again this is not the case with unmarried or non-civil partners. So even if Martin had left a Will leaving his Isas to Frances, they would have still lost their income tax free status. 

As an aside, in terms of gifts on death to individuals, only spouses and civil partners are exempt from inheritance tax.

Back to the 1975 Act. For a cohabitee to bring a claim there must be evidence of having lived with the deceased full time for two years before death. Interestingly case law does not restrict living together as just one house. Martin and Frances could have gone from him to her house to her to his house and it still would count. 

For cohabitees, claims under the 1975 Act are almost always limited to maintenance only. This means keeping a claimant in their accustomed lifestyle, but not going beyond that. The nuts and bolts of these cases are an analysis of a claimant’s capital and income versus expenditure. This can be intrusive. 

Frances would need to show she is worse without Martin and limited in what she can now afford, compared to when he was alive. Frances has a home to go back to and the issue will be whether she can afford to live there on her own and do what she did with Martin (e.g. have holidays) without additional funds from Martin’s estate. 

This is a tough call for Frances at a time she is most likely not at her most robust. I regret that my final point is that there is a time limit here. Frances must issue a formal legal claim within six months of Martin’s children extracting a “grant of representation” from the Probate Registry to deal with his estate. They will need this document to sell his house. 

I wish you and Frances well in your deliberations. The 1975 Act is there to rescue the financial situation of people who are bereaved and then have a second shock of being left financially insecure. Please do the sums and if Frances is one of those persons, she must think very carefully about bringing a claim.

Ask a Lawyer is written by Gary Rycroft, solicitor at Joseph A Jones & Co, and published twice a month on Mondays. Email your questions to askalawyer@telegraph.co.uk