inheritance payments.

Hi All, looking for a bit of advise
I am in reciept of income related ESA.
I have been named as a benificary in the will of a relative who as passed away.
my inheritance will be paid to me once probate is granted and all outstanding matters are dealt with by the estate adminastrators, I have been informed that due to backloogs, coronovirus and complications with the estate that this could take between 12 and 18 months. I will recieve my inheritance from the residuary trust fund which is paid out after all other matters are settled.
the ammount I recieve will put me over the savings threshold.
when do I inform the DWP, now, or when the money is paid into my account. ??
Thankyou