Two things I forgot to mention:

1) It definitely won’t look good in court for the tradesman if they try to collect the £2.5k but haven’t provided any written quote for the work in advance.

2) If they try to add VAT on top of the figure you say they quoted for the work, do not stand for it. They should have quoted you a VAT inclusive price as it should have been obvious to them that it was work of a domestic nature for a customer who was not a business.

With regard to what others have written, I think I might be inclined to let them attempt to sue me, before offering any payment. Definitely do not stand “debt collectors” turning up trying to get the money. No one can legally do anything against you, ie seizing goods or taking money (unless you want to pay) without a court order. And you will get advance notice of any hearing anyway (any claimant is required to send a “letter before action” prior to that too).

In a situation when my tenant found himself locked out, and rather than calling the out of hours locksmith on the managing agents email, he found one online and then paid over £1k for a £250 job and asked me to reimburse him.
The managing agents resolved it by getting their own locksmiths to quote for the work and emailed the tenant with this, who contacted Head Office who agreed to refund him.
They dismissed it as an employee getting a bit carried away. More like he saw an easy mark and defrauded him.
But your best bet is whoever is in charge of this firm, backed up by a quote from a reputable drainage specialist as to what this sort of work should cost (hopefully someone will agree to give you a ballpark max figure by email if you can send photos, number of men and hours spent at the job). I got a roofer to do that when I was worried my elderly parents had been ripped off, and he reassured me that although he would have charged a bit less, they’d done a good job and what they’d charged wasn’t criminal.
You can also get Trading Standards involved, it’s their job rather than pay a solicitor yourselves. Might your buildings insurance also cover this? Either the work, or defending an unlikely legal suit by the contractors?
Good luck, it all sounds horribly stressful.

I would relax about this. The law is on your side for two reasons.

Firstly I suspect they have not sent you an invoice? If they have not sent you an invoice they can't easily take any action through the courts to enforce the alleged sum owed. If they have sent an invoice query it and ask for a detailed and costed breakdown and simply state that the invoice rendered is unrelated to the verbal quote that you have received. Yes, it should have been a written, emailed quote, but that is water under the bridge now. Also if the 'invoice' doesn't state the company registration number and their VAT number query it on that basis. If they claim to be VAT registered the invoice must have the VAT No on it. Then check the VAT number relates to the company on the gov.uk site https://www.gov.uk/check-uk-vat-number.

Secondly, as one of the other posters has said, if they turn up at the house call the police. If they try and rip their work out then it is a simple criminal damage. The law is very clear on this wrt to domestic building works that once goods and materials are affixed to the house/premises they cannot be removed without the building owner/lessee's consent.

I would be careful of becoming a cowboy investigator and starting to recored conversations as the recording may well not be admissible in proceedings as they were covertly obtained. But, I would keep a hand written contemporaneous diary of that is said by whom when.

To take control of the situation, what I would do is to ask for a breakdown of the purported costs and how they are calculated to be delivered up in writing within seven days for your consideration. Do it by email. I would then go back with a reasonable offer of settlement which is in line with their original quote and show a simple, fair and clear calculation of how you have arrived at it. For instance if they gave you and hourly rate card for their workers beforehand you have to use those prices. If they show you an invoice for materials, cross check them online, but you are probably stuck with those costs even if they are, as an example 40% OTT, because that was what they paid actually for them.

I wouldn't waste money on a solicitor at this point. Keep it simple and report back how it rolls.

Good luck.

Good Morning, when they asked you if you could pay in cash it should have sounded alarm bells. Ask them for a detailed breakdown of the costs, labour, materials and plant. £2.5k is what I would expect to pay two skills for 5 x 8 hour shifts. Specialist equipment? Everyone in the construction industry has their own tools and equipment as part of their kit. Unless they were micro tunnelling I don’t know what specialist equipment they could be using in a property. I do a lot of work in construction, I don’t know of any skilled work that costs £2.5k for 5 hours unless the materials are very expensive. Be careful of these websites, the builders pay to advertise on them so they can take down or they can put up good reviews about themselves. Alway get a recommendation from someone you trust not a website. My neighbours are constantly getting ripped off by getting trades from these sites. Beware

chorister wrote: ↑Sat Aug 20, 2022 10:06 pmIf you are paying £500 - £600 + VAT for a solicitor's letter for something like this then you've got the wrong solicitors…

Unfortunately, they all seem to be the “wrong solicitors”

If you are paying £500 - £600 + VAT for a solicitor's letter for something like this then you've got the wrong solicitors.  But may be the best thing is to offer payment and if they don't accept it then do nothing - see if they pursue you.  And as @atbattersea says, record everything.

Solicitors have a habit of charging, and charging, and charging… so unless they can resolve the problem with a single letter (likely to cost you £500-600 plus VAT), it is unlikely they are going to save you more money than they cost… Although you may prefer to pay the solicitor than the rip-off tradesman.

The crux of the problem here is what you have agreed to in terms of services provided and the cost of those services. This constitutes a contract, and enforcement of that contract is the only way the tradesman is going to be able to force you to pay, legally.

The problem you have is that you only seem to have a verbal contract - so a judge is going to have difficulty assessing the truth of the matter.

However, the fact that the tradesman is asking for cash payment, and is apparently issuing threats to "rip up the work", tends to support your veracity rather than the tradesman's.

What you need to do is write down everything that happened, and how you agreed to the work for a certain sum. Then also state how that seemed to change, without any further discussion. If you have emails to support your version of events, then that also helps, as do text messages and phone call records.

Going forward, contemporaneously write down each interaction you have with the tradesman/office, and record telephone/in person conversations if you can.

Offer them the fee you believe that they quoted for the work, in full and final settlement. If they refuse it, send them a cheque for the money, with a letter saying that if they cash the cheque they are accepting it as full and final settlement.

If they start making further threats to rip up their work, make sure you record these in some way. If they turn up to your house, refuse them entry and tell them that if they do not leave you will call the police.

It seems unlikely to me that, if they are trying to con you, that they will attempt to enforce the contract in court, but if they have issued an invoice (or the claim is otherwise made) they have up to six years to take that action. But you should be prepared to fight them in court if necessary, so keep the records I have indicated above.

You could try contacting your local trading standards department, but I have found it very difficult to get them interested in anything in the past.

First of all take a really comprehensive set of detailed photos of the work as it stands now, in case they are stupid enough to try to rip it up.  Then get a good solicitor - I recommend Alexandra Adam at Gregsons in Wimbledon.  The cost of the solicitor will be way less than the amount they will save you.   And check if the company is registered at Companies House.

And make a note of how many people were in site and for how long - it shouldn't be too hard to find out the going rate / hour for reputable people.

Advice/experience with a tricky question to do with paying for a service.
We recently discovered we had a problem with a drain, and looked up a few drains companies. The one my husband found seemed very responsive and helpful. However he's not great with digging around the internet, and it seems he didn't hear me say 'make sure you look up Trust Pilot'! To be fair he was super busy at the time and we were both juggling a few admin things as well as work.
The company took great pains to exchange detailed emails about the cost of coming out to assess the problem, asked for photos before they confirmed they could even do an assessment, and seemed very thorough.
On the day they did the assessment they confirmed what they thought the problem was, and verbally told my husband what the cost would be. They were available to come back the very next morning at 9am.
They came promptly the next morning and seemed very thorough and thoughtful. They were careful with removing tiles and careful with putting them back. They had lots of specialist equipment they needed to use and they seemed very good - it wasn't a minor job and it took 5 hours.
When the work was done, they asked my husband if he could pay in cash, but only when they were asking did he realise that they thought they were asking for a very large amount of cash. He then realised they were asking for £2.5K! When he thought the job was way less than £1K. Now we do accept that we were really stupid not to get the quote in writing - so stupid! But my husband is convinced that he heard what he heard. Of course we don't have that kind of cash (plus he works for company who would probably fire him if he was helping people avoid tax so we wouldn't pay in cash anyway). The guy waited around for quite a while waiting to be paid in cash while we exchanged calls with company office.
I went on Trust Pilot and needless to say there are some pretty dire reviews of this company - none exactly the same as ours - although a few references to extortionate costs. But certainly a lot of 'avoid this company'. 
Now we don't want to be assholes and not pay people for a good job done, and we have to take responsibility for being stupid enough not to get a quote in writing.  However nor do we want to be fools and just pay over 'whatever' someone says - which is a seriously substantial amount of money. They are now saying that as we won't pay cash anyway, the bill is in fact £3K but they'll give us a 'generous' £500 discount so we still only have to pay them £2.5K. If we don't pay the full amount they say they'll come back and rip up their work...
Any advice and experience greatly appreciated...