You didn’t get a place for the London marathon on the ballot and had given up on the hope of taking part this year. But then someone in a discussion group on your running app posts that they are injured and are selling their place.

After contacting them on WhatsApp, they say they can transfer the place once you pay £79 via bank transfer, and give your full name and email address.

But the sale is a scam, timed for the weeks before the event on 26 April when excitement is building among runners who want to be part of one of the most famous races in the world.

The organisers of the London Marathon say there are “no circumstances” when a marathon entry can be transferred from one person to another.

“It is a total fabrication for anyone to suggest that a TCS London Marathon place can be sold or transferred,” they say.

Many of the legitimate runners take part for a charity … and the costumes are all part of the fun. Photograph: Zac Goodwin/PA

“For many reasons, including medical ones, all places in the TCS London Marathon are strictly non‑transferable. Our terms and conditions of entry make clear that participants cannot swap places, or allow another person to use their bib number.”

What it looks like

Like many scams, it has poor grammar and punctuation.

“Hello everybody I’m still looking to sell my ticket, If anyone missed out on a spot in the marathon entry. I it and would like to transfer my registration,” it says, then gives a number to contact on WhatsApp.

Once contacted, the scammer says the place was won in a ballot but can be changed on the marathon’s website once the victim sends their details over and pays a £79 fee. The real entry fee is £79.99.

What to do

The organisers of the marathon say you should sign up only through official channels, which for most people means entering the ballot, or running on behalf of a charity.

There are a number of red flags signalling that the sale is a scam. One is being asked to pay via bank transfer, which offers none of the protection that come with card payments, such as the section 75 protection when using a credit card. Another is poor spelling and grammar.

If you believe you have been defrauded, you can contact the London Marathon organisers through the official website, and contact Report Fraud. Try to log all interactions you have had with the criminal.

Fitness app Strava says: “Deceiving, misleading or defrauding others, or encouraging inauthentic interactions, is prohibited, and any violating accounts will be suspended. This includes exploiting bib transfers to defraud others.”

It has ways to report profiles violating its policies on its site.