Also be aware if she's been in a NH for a while, 3 yrs I think, you may have to pay capital gains on the house. The difference between what it was worth when she bought it and what she's now got for it.
I wish I'd known about this clause before, as Mum's been in her Home 4 and a half years now and so it now counts as an asset as opposed to her 'home'.
I do sympathise, as once the house is sold the loss of rental income and low interests these days mean their money runs out even faster.
If the house was unoccupied the time limit is 18 months, it used to be 3 years.
The capital gain is time apportioned over the period it was owned and it is only for the last unoccupied period that the gain is chargeable.
So difference between purchase price and sale price divided by number of months from date of purchase to date of sale, gives you the gain per month. Then if it was 4.5 years after moved into home, then 36 months of the gain per month is the chargeable gain. There is then an annual exemption to deduct as well of £11,000 - so if the 36 months time the gain is less than £11,000 then there is no tax.
I should add the example is very simplistic, and if part of the house was inherited from the spouse the cgt calculation will be much more complicated as it is in my mum's case. Her half of the house was purchased in 67 but dad's half of the house became hers when he died in 94 and is valued at house prices on that date (so lower gain in total but complex calc).
If the person whose house it is does not prepare a self assessment return, then you will need to notify HMRC they fall into self assessment for the relevant year so that returns are issued. There are time limits on this as well.
HMRC also receive all listings of house sales from the land registry, and match them to the council tax register. If there is no one resident they start a tax enquiry and a minimum penalty of 20% of the tax is likely to be charged so please don't consider not advising of sale. I see several people caught this way each year.