Arthur died in 2014 and his wife Beatrice died in May 2017.
Supposing Beatrice’s estate is entitled to the maximum RNRB (£100,000), she will also be able to apply the unused percentage of Arthur’s RNRB on top of that. His unused percentage is 100%. 100% of the maximum RNRB at the time of Beatrice’s death is £100,000.
Therefore, Beatrice’s estate will have an RNRB of £200,000 (her own, plus Arthur’s).
It is the unused percentage that is transferred not the amount. This is significant when different tax years are involved. If Beatrice had died in May 2018 instead, the maximum RNRB for that tax year is £125,000.
In the 2018/2019 tax year, 100% of Arthur’s RNRB equates to £125,000 – rather than the £100,000 in the previous example. Beatrice’s estate would therefore have a total RNRB of £250,000 – own £125,000 plus £125,000 from Arthur.