TRS who pays the fees?

[AK2021]

I am helping with an estate where the deceased had a life assurance policy in trust.
Last October before the DOD, he was told by Aviva that the trust must be registered, and no pay-out would be forthcoming until it was,
He instructed his solicitor to do so, but this didn't happen until, prompted by the executors, after the DOD.
The question is who pays the solicitors fees for this.
The estate - as a debt owed by the deceased.
The estate - just call it an expense and hide it among other fees from same solicitor.
The trustee - does that then become an expense of the trustee and re-claimable from trust funds
The beneficiary - trustee deducts it from the funds before distribution

In the big scheme its not a huge amount, but given that gifts will abate it feels important that correct accounting is followed.

My understanding is that if the deceased had paid the fees, while alive, it would have constituted a further settlement, and accounted as such for IHT. is this correct?

[AGoodman]

The trustee has the obligation to register so I would expect the liability falls upon them - and yes, they have a right of reimbursement from the trust fund.

It is not really anything to do with the estate.

Interesting (but not surprising) that the insurer is asking to see evidence of registration. I imagine most of these trusts are non-compliant.