12. Pay early to avoid paying interest
You can make early Inheritance Tax payments before you know the exact amount the estate owes (this is known as a ‘payment on account’).
HM Revenue and Customs (HMRC) will charge you interest if you don’t pay all the tax the estate owes by the due date. If you won’t know how much Inheritance Tax the estate owes by the time the payment is due, a payment on account can help you avoid some of the interest.
If you overpay
If you pay more money than the final bill says the estate owes, HMRC will refund the excess after you’ve been given probate (confirmation in Scotland). Probate is the right to deal with the deceased person’s property, money and possessions.
HMRC will also pay interest on the amount you’ve overpaid.