Possible to claim transfer of unused NRB if Executor and Will cannot be located?

Shedman

Mother-in-Law died recently and her estate is around £35-40k over NRB.  There will be no IHT payable as she will have RNRB of £175k downsizing allowance from property sold to fund care home fees.  I would love to keep things as simple as possible and avoid IHT400 if we can but we cannot claim it as an 'excepted' estate as it stands, unless we are able to claim for transfer of unused NRB from her deceased husband.  

The problem is that he died over 40 years ago in 1981 and nobody has a copy of his will or knows who the executors were.  I have searched Probate Office and there is no evidence of probate being granted.  It is believed that he left everything to his spouse (i.e. my MiL) and that house was held as joint tenants.  Alternatively there may have been no will but his estate was below the threshold and all passed to his wife under the intestacy rules (threshold being £40k in 1981 before anything went to offspring as well as far as I can determine)

None of the 3 children received any inheritance from him at time of his death and to best of their recollection (bearing in mind they were 22, 20 & 18 at the time) it was highly unlikely he made any gifts in 7 years before his death. Therefore, it is almost certain that there would be a full NRB available, which I believe was £50k in 1981/82 tax year which would be sufficient to make MiL's estate an 'excepted' estate.

Is there anyway of claiming the transfer of this unused NRB in this situation with such a lack of evidence of how his estate was handled, given that IHT216 asks for a copy of the will if one was made? 

Any advice gratefully received. 

Keep_pedalling

This is quite a common issue as often there is no will on the first death where someone dies young, and probate is rarely needed either. I think it would be a safe assumption that your MIL inherited all of your FILs estate either from a long lost will or intestacy rules of the time so you can claim the TNRB. If probate was not applied for at the time then not only do you have no records, neither do HMRC, so this is not open to challenge. 

You are correct about the rate being £50k at the time, but the amount claimable is based on the unused percentage applied to the current allowance so if you needed it the full £325k would be available.