// A Beneficiary will not usually be liable to pay Capital Gains Tax on their inheritance. However, if an asset is transferred to them from the Estate (such as shares or a property, for example) and they then sell this at a later date for a profit, they may become liable for Capital Gains Tax at this stage.27 Feb 2019//
Sister A who died in 2013 - there has been an IHT event and so the gain for the husband is counted from 2013 ( you need a valuation at 2013 - available from any estate agent - but - - - the valuation for the IHT purposes in 2013 will do.). So he enters the date of acquisition as the date of her death and that is the date for the valuation.
Sister B - her CGT will be from date of purchase ( sister A's death does not affect her)
You (they) need to register for CGT on the internet
they really need to do this now
https://www.gov.uk/capital-gains-tax/report-and-pay-capital-gains-tax
You have to enter the details and pay the moolah within four weeks of completion.
it is not that bad - the site is easy to use. The only thing is that if the gain is £134 000 - not impossible in todays climes - some tax may be at 18% and some at 28%- the machine does it for you.