The increase in probate fees from May this year will mean that higher value estates will have to pay up to £20,000 in Court fees on top of any inheritance tax.

The government's justification is that the fees will help fund the Court System.  This article suggests that as the majority of high value estates will contain a house, the new 'fee' is really a way of taxing the increase in value of family homes which are exempt from Capital Gains Tax.  

Whatever your views about the motivation for the new charges, if you are dealing with a deceased person's estate at the moment get your probate application in as quickly as you can while the fee is still £155 regardless of the value of the estate.