2. Get a payment reference number
You’ll need to get an Inheritance Tax reference number from HM Revenue and Customs (HMRC) at least 3 weeks before you make a payment.
You can apply for one:
- online (unless you need it for a trust)
- by post - using form IHT422, Application for an Inheritance Tax reference (the address you need is on the form)
Do not use the 15-digit number from the online Inheritance Tax service to report an estate’s value.