Basic principles: claims
There is no requirement for a claim to be made for RNRB. If the conditions for RNRB are in point then it is due automatically. Claims are, however, required for an entitlement to a brought-forward allowance (IHTM46040), or for a downsizing addition (IHTM46050).
If there is more than one property that the deceased has occupied as their residence, the personal representatives need to nominate which property is taken into account for RNRB before any RNRB is due (IHTM46011).
You should apply RNRB where it is clearly due whether or not it has been claimed. Situations where RNRB is clearly due include:
The deceased dies on or after 6 April 2017. The estate includes only one residential property and this is shown as the deceased’s last usual residence on the IHT400 and the whole estate is left to the deceased’s children or grandchildren.
If RNRB appears as though it may be due, but you do not have all the information to be certain, you should draw the possibility to the parties’ attention and ask them to complete form IHT435. The form IHT435 requests the information necessary to establish whether, and if so how much, RNRB is due.