More than 250 reports of rogue trading are made each year across the county but it is estimated only between five and 20 per cent of these crimes are reported.

Hertfordshire County Council's Trading Standards team has warned vulnerable people not to buy goods or services from anyone who calls at their doors.

The council has also advised people to agree pricing beforehand including VAT as there is no evidence without a written contract.

Richard Thake, in charge of community safety at the county council, said: "Hertfordshire County Council is committed to keeping residents safe, so we recommend that everybody reads and shares this advice, particularly with vulnerable older relatives and neighbours.

"If you’ve been targeted by a rogue trader, do not let them get away with it. Always report anything suspicious to our Trading Standards team."

Russell Reeder, principal trading standards officer at Hertfordshire County Council said it may be tempting to just find someone in the phone book or say yes to the trader that has just knocked on your door but you do not know that you will be getting a fair price or a good service.

He said: "Our partnership with Which? Trusted Traders helps consumers to find reliable traders who have been thoroughly assessed and checked."

Hertfordshire County Council has advised people to follow these steps:

1. Say no to doorstep callers. Do not buy goods or services at the door.

2. If you are considering having work done, always shop around first and get at least three quotes.

3. You can search for a Hertfordshire Trading Standards Approved Trader on the Which? Trusted Traders website or by calling Trading Standards.

4. Honest businesses agree pricing beforehand, including VAT. There’s no evidence without a written contract.

5. Avoid paying cash in hand. It’s better to pay by bank transfer or cheque, as these can be traced.

6. If you think you or a vulnerable relative or neighbour has become the victim of a rogue trader, report it straight away.

Have you been a victim of a rogue traded? Comment below or email steven.brown@london.newsquest.co.uk.