How is a prospective buyer's "cash offer" qualified when they are homeless?

My property is listed for sale with an online estate agent and I paid extra for them to deal with all viewings. I live some 10 miles away from this property with my husband.

And, yes, I unwittingly accepted an offer from a homeless person ... needless to say, this "sale" fell through!

Once I accepted the cash offer at the full asking price, I was inundated with messages direct to my personal email address. This personal information was accessed by the "buyer" from the agency's online portal. This buyer first asked to rent my house "until completion" or be allowed to use my address as their mailing address. Needless to say, I declined.

Apparently, an estate agent is able to qualify a person's cash offer even when they are homeless and living in a camper van! That was news to me!

The estate agent saw the person's online bank statement or a screenshot of this - he wouldn't elaborate any further - I think all of his checks were carried out online, not in person.

I have complained about this but a director of the online estate agency says that this is a perfectly acceptable way of qualifying an offer. He stated that the 'buyer' had a solicitor, so their status wasn't an issue.

However, although the buyer had entered a a legal firm's details at the portal when they put forward the offer, they almost immediately removed this information. They had not formally instructed a solicitor ! The buyer disclosed to me that they were struggling to instruct a solicitor because of the homelessness issue. This was where I was meant to step in and go to their rescue.

Obviously, I'm not foolish enough to give a homeless person permission to use either of my properties as their mailing address!

Regrettably, by the time I discovered that the buyer was homeless, I had already formally accepted their offer through the agency's portal. Approximately four other potential buyers' viewings had automatically been cancelled at the agency's portal and, from online reviews, I gather the messages from the agency are blunt. In addition, my property's status was changed to "sold subject to contract", both online and on the for sale board. I made a special journey to where my other house is to remove the 'SSTC' notice from the for sale board, in the hope that it would not put people off viewing.

In the three weeks since the bank holiday weekend, although we have reduced the price, there has been much less interest in my house. The house is in a village and I expect people will think that it has had a dodgy survey and is too risky a prospect.

What a nightmare... next time I sell a house I'm going to employ a local estate agency on a "no sale, no fee" basis!