accepted deposit but buyer dissapeared

[therenter]

Can anyone advise us please? My dad advertised something for sale on gum tree. A buyer contacted him paid the 100 deposit in cash on a thursday and then said he would ring the following Monday (just gone) to pay the remainder and collect the item.The guy still hasn't been in contact up to today.
My dad didn't take his contact details so has no way of getting in contact with him.
How long should he leave it before he re advertises the item? And is he legally obliged to return the deposit if the gentlemen eventually does contact him?
Thanx

I would think he could re-advertise, but keep the deposit for a month & return if contacted but sell the item to someone else who can pay & collect it.

However I am not a legal person so I watch with interest to see what advice you get!

What percentage is the £100 of the total? If a fair bit I would wait to see if something had happened, might have had a family emergency, lost mobile. It would be hard to sell it to someone else if he/she had paid a fair deposit.
Might also be waiting for pay day?