After setting up a website and email address, a reporter gained a handyman profile on Rated People and MyBuilder.
He was also able to pretend to be one of his customers and submitted glowing reviews for extra credibility.
MyBuilder said it would review its processes, with Rated People calling its screening methods a “top priority”.
The websites provide a network of people or companies offering a variety of services including plumbing, roofing, bricklaying and landscape gardening.
Users can filter results by their location and can also read reviews and ratings posted by the tradesperson’s previous customers.
While several similar sites required a face-to-face meeting, references or proof of public liability insurance, the reporter was able to start advertising as a handyman on the two websites with relative ease.
Rated People did not ask for references, insurance or request any quality checks and MyBuilder’s property maintenance questionnaire was passed by searching the internet for the correct answers.
Phillip Norton: From BBC reporter to wannabe handyman
I was incredibly surprised by just how easy it was to get signed up and how simple it was to award myself a reliable-looking five star rating and positive feedback.
With the help of friends and false email addresses, I could set up fake work, apply for it, and build myself a trustworthy profile without lifting a finger.
With a website and rented business premises, we went to some lengths to make Inside and Out Property Services appear like a legitimate company. But it turned out very little of that was needed.
Rated People and MyBuilder have both told the BBC they encourage property owners to do their own homework and check reviews before hiring.
But many people turn to trustworthy trader websites thinking a large part of the homework has already been done – a belief for some that’s proved to be an expensive mistake.
Location, Location, Location presenter Phil Spencer, an ambassador for Rated People, said it was “shocking to hear that some bad tradesmen get through the net”.
David Ball, from Prescot, Merseyside, handed over £1,500 to a tradesman he found on the website to repair damp but he failed to treat the problem and is now “nowhere to be seen”.
“I thought they had a process in place to make sure the people doing the jobs were trustworthy,” Mr Ball said.
“You go through an external company because you think there’s a level of protection there you’re not getting if you’re going direct.”
The tradesman involved has since been removed from the service.
Rated People said tradespeople looking to sign up were screened with a credit agency, fraud prevention agencies and it “regularly reassesses all members”.
Accreditation is required to be validated “where official government accreditation is available”, but “no formal qualifications or standards exist” for a handyman, a spokesperson added.
MyBuilder said it turned down 40% of all applications, with each trade category evaluated differently due to varying requirements.
The handyman evaluation is “the easiest to pass” as jobs in the category are “relatively low skilled and low risk”, including assembling flat pack furniture or hanging pictures.
Despite this, the company said it would still be “conducting a thorough review” of its handyman evaluation following the BBC investigation.