How to find a rent guarantor

The easiest thing would be to act as guarantor but you'd still remain liable for unpaid rent I think.
If you could be 100% sure that the rent would get paid then going guarantor is the best.
You'd have to have absolute surety on this from your daughter as it sounds as though they've been reckless, knowing that you're a safety net.
I haven't heard of the other method.

Well done for refusing. It could be a potential nightmare, and leave you penniless. I would just keep looking for a landlord who doesn’t ask for it. I’ve not heard of this other thing either. No harm in finding out about it.

I let a house that I inherited. My contract with the agent includes a rent guarantee and this costs 5% of the rent each month. I don't know of any that are as cheap as £250 a year and to be honest I'd be suspicious of them. I don't know how they'd charge so little.

I think I'm right in saying that the rent guarantee is for landlords not tenants. After all the tenant could take the guarantee and then just stop paying rent!

I know that my guarantors would not allow me to rent to tenants with a history like your daughter. It is too risky for them

It is also very risky for you, so please stick to your guns and refuse to stand as guarantor. You could lose a lot of money.

The arrangement you mention (charging £250 to guarantee rent) sounds dodgy to me. How to they recoup unpaid money, and what methods do they use?

Sorry, I can’t offer a better solution, but personally, I would avoid that one, as it conjures up visions of Phil Mitchell coming round with a baseball bat.

I was a guarantor some years back and its not just a case of giving a name to the landlord. The letting agents wanted proof you could afford to be a guarantor. Eg payslips, details of your savings ,Proof of employment and credit reference checks are made. Not as straight forward as your daughter might think. Are there any housing associations near you they could approach for advice?