GOV.UK
1. Overview
You must get an Inheritance Tax reference number before you can pay Inheritance Tax.
You can apply for one:
- online unless you need it for a trust
- by post - the address you need is on the form
You must apply for an Inheritance Tax reference number at least 3 weeks before you want to make a payment.
Making ‘payments on account’
It may take you some time to finalise the financial affairs of the person who has died. You can make early Inheritance Tax payments before you know the exact amount the estate owes - these are called ‘payments on account’.
If you do, HM Revenue & Customs (HMRC) may pay interest on these payments.