It really is ‘who you know’ – as Brits reckon the best people to have in their phone books are a plumber, an electrician and a gas engineer. 

A poll of 2,000 homeowners found mechanics, hairdressers and roofers are also good to have in your list of contacts.

For 75 percent, they would only ever trust a friend or family member or someone recommended in the trade to carry out work for them.

And 29 percent of those who have had work done by a big company with no personal contact claim they have been overcharged.

The study was commissioned by Gas Safe Register, which has released the 'Gas Safety Guardians’ calendar starring registered UK engineers to mark Gas Safety Week from Monday (11th September).

Spokesperson Rob Denman said: “There’s the famous saying ‘it’s not what you know but who you know’ and that seems to be borne out by these results.

“It’s really important to have trust in the tradesperson you hire.

"One of the things you can do to help instill that trust and ensure your job is being done to a proper standard is to check they are fully registered or accredited and have the certification to prove it.”

Of those who’d only use someone they knew to work on their home, 51 percent sad this is because they know they’ll get honesty from them. 

While 38 percent are confident they won’t get overcharged for work, while 12 percent reckon the job will get done quicker.

As a result, 79 percent are likely to recommend someone they know to friends or family.

And 64 percent said having a well-stocked little black book of contacts is the best way to get through life.

It also emerged the top attribute of a good tradesperson is considered to be reliability (76 percent), followed by trustworthiness (72 percent) and qualifications (65 percent).

With a gas safe engineer considered the most trusted tradesperson, with 25 percent of the vote.

However, nine percent admitted they’re unlikely to check any tradesperson is registered with an industry body before using them.

Worryingly, 11 percent have had work carried out in their home by a tradesperson it later transpired had no qualifications or even formal training. 

This led to 36 percent of those regretting their decisions ‘very much’, according to the OnePoll.com figures.

While 79 percent regretted not checking out their credentials.

Gas Safe Register’s spokesperson added: “Some areas are riskier than others when it comes to training and accreditation.

“But having your appliances serviced or having work completed on them by someone who isn’t qualified to do so can be costly – and is best avoided.

“We want to remind homeowners that prevention is better than cure, especially when it comes to gas safety and keeping you covered for the unexpected.

“Our engineers are incredibly knowledgeable and passionate about what they do to keep the nation gas safe, and the role they play in our communities – and releasing this calendar gives us an opportunity to champion and hero them.”

To have the chance to win a £50 Amazon voucher, carbon monoxide (CO) alarm and a copy of the limited-edition ‘Gas Safety Guardians’, go to Facebook.