Very often parents are in the unfortunate position of having a son or daughter who for reasons of capacity, mental illness or drug/alcohol addiction are unable to manage money particularly well for themselves. Parents sometimes consider leaving that son or daughter’s share to another child to manage for them. This can be complicated and often cause more issues.
Say that you have a son and a daughter - your son is unable to manage money for himself so you leave his 50% share to your daughter for her to manage. Should your daughter ever get into financial difficulty in her lifetime, her creditors will go after all her money including the sons. Should your daughter pass away before your son, any money that she has would pass onto her husband/civil partner or her children leaving your son with nothing. Should your daughter get divorced she could lose your son’s money in a divorce settlement.
The correct way to deal with this case, is to pass both your son and your daughter’s share to them individually, however, your son’s 50% share goes into a Discretionary Trust. Your daughter or others are set up as the Trustees for the Trust but this ensures that everything you leave to your son is protected from all of the above.