Judges have stressed the importance of making wills after ruling in the case of two stepbrothers fighting over their share of a £500,000 estate.
Martin Densham-Smith had claimed he was entitled to a half share of the money left by his father's second wife, Laura Densham-Smith, of Cobham, in Surrey.
But Jonathan Fry, Mrs Densham-Smith's son from her first marriage, claimed he should be entitled to the whole amount.
Court of Appeal judges ruled the two sons should share the money equally.
They upheld a ruling that Mr Densham-Smith's father Denny and Mr Fry's mother had made an oral agreement for mutual wills.
'Ring of truth'
Mr Fry, 51, had appealed against a finding at Guildford County Court, claiming it was not supported by the evidence.
He claimed that his mother was not bound to leave half to Mr Densham-Smith, 58, when she died in 2005, 15 years after her husband.
None of three wills she made after her husband's death left anything to Mr Densham-Smith, and her final will left almost everything to Mr Fry.
At the Appeal Court on Friday, the judges dismissed Mr Fry's appeal, saying the findings on "what was probably agreed and done have the ring of truth".
Lord Justice Mummery said: "Ideally, Denny and Laura should have gone to solicitors with instructions that led to the drafting and execution of wills recording a mutual wills agreement."