In Short
Most Black Friday offers on windows and doors are not discounts. They are the same price, presented differently. Windows and doors are made to order and priced by software against your exact specification, so there is no stock to clear and very little to mark down. Since 6 April 2025 a false claim that an offer ends on a set date has also been a banned practice in UK law. Judge any November offer by what it adds to the specification, not by the percentage.
My name is Nick Dardalis. I have worked in UK windows and doors since 1989. Every November the trade advertises Black Friday deals on products that cannot sensibly be discounted, and every year homeowners ask me whether they are real. My answer has not changed. What has changed is the law, and what the deadline is now costing you.
Black Friday falls on Friday 27 November 2026. Offers will start appearing in the first week of November and a good number will still be running at Christmas, which tells you most of what you need to know about the deadline.
What has changed since 2024. The offer itself may now be unlawful
The Digital Markets, Competition and Consumers Act 2024 brought a new set of consumer protection rules into force on 6 April 2025. The Competition and Markets Authority can now enforce them directly, without taking a company to court first.
Those rules include a list of practices banned outright, whatever the circumstances. Three of them describe the window and door sales routine with uncomfortable precision.
Banned practice 7 is “falsely stating that a product will only be available for a limited time”. The CMA’s guidance gives a countdown clock as one example, and an item advertised as available for five days that was offered again ten days later as another.
Banned practice 26 covers creating the impression that you cannot leave until a contract is signed. Banned practice 27 covers ignoring a request to leave your home. Banned practice 32 covers telling you that the salesperson’s job or livelihood depends on your decision tonight. The full list is in the CMA’s unfair commercial practices guidance, CMA207.
In November 2025 the CMA opened its first investigations under these powers. One of them concerns whether a retailer’s time-limited sales genuinely ended when they were advertised to end. It also issued around 100 warning letters to businesses across several sectors, and published final guidance on price transparency.
None of this means that a company advertising a November offer on windows is breaking the law. It means the claim now has to be true, and the company carries the risk of proving it. If the price really was higher a month ago at the same specification, and the offer really does end on the Friday, they should be able to show you both. So ask.
Why a real discount is almost impossible in this industry
Windows and doors are not off the shelf products. Virtually everything sold in the UK is made to order, to the measurements of one opening in one house. There is no warehouse of standard sized windows waiting to be cleared at the end of November. The exceptions are a mismeasure or a cancelled order, and those are someone else’s sizes, not yours.
Pricing is personalised and software driven. The days of a salesperson working through width and height charts in a ring binder have gone. They would price to the next size up, which left room to come down later, or to keep as margin and commission if they did not need to. Today the quote is calculated against your exact specification. In a manufacturing business that software is usually linked to the factory and produces the cutting lists, machining data and material schedules from the same figures. There is very little slack in it to give away.
So when a percentage appears, it has almost always been built into the price first. Discounting a made to order product is a decision about margin, not about clearing stock, and the companies with the least margin to give are the ones advertising the biggest reductions.
This is not unique to our industry. Which? tracked 175 products across eight retailers from May 2024 to May 2025 and found that 83% were cheaper or the same price at some point outside the four week Black Friday period (Which?). Those were mass produced goods with real stock sitting in real warehouses. Ours are not.
Ignore anyone telling you they have old stock or windows on clearance. Your windows do not exist yet.
The tactics, and where they now sit in law
The industry earned its reputation. Hours spent in the customer’s front room. The discount ladder, 30%, then 40%, then 50%. The manager’s special, phoned in from the car. The board left in the front garden in exchange for money off. The price that was only good tonight.
Those tactics did lasting damage to trust, and they are the reason most people now assume a window discount is invented. Several of the national companies built on that sales model no longer trade in the form they did.
What is different now is that the behaviour is written down and numbered. If a salesperson tells you the price holds only until Friday and it does not, that is no longer just sharp practice, it is a banned practice. If they will not leave when you ask them to, the same. You do not have to win an argument about whether it is fair.
The simplest response is also the most effective. Say that you will take the quote away and decide next week. Then see whether the price survives.
Free fitting, and the offer that is really finance
Fitters are paid for what they fit, not by the day. A uPVC window replacement is not the same job as a six metre sliding door, a structural glazed opening or a bonded aluminium system, and the rate reflects the skill involved.
Those costs sit inside the price of the product. A company offering free installation has either moved the cost somewhere else in the quote or is not paying the fitter properly, and neither outcome helps you. Ask what the fitting is worth and who employs the fitter.
The bigger change since 2024 is that the headline offer is often not money off at all. It is 0% APR, a deferred start, or a monthly figure.
Finance is a perfectly reasonable way to buy windows and it suits plenty of households. It is not a discount. The lender is paid a subsidy to provide the rate and that subsidy sits in the cash price. A 0% deal and a price reduction are alternatives, not a package.
Ask for two numbers side by side: the cash price, and the total amount payable under the agreement. If the company will not give you the cash price, you are not being offered a choice. Check that whoever arranges the credit is authorised on the Financial Conduct Authority register, and note that buy now pay later came under full FCA regulation on 15 July 2026, so shorter deferred payment offers now carry proper disclosure.
In November, the deposit matters more than the discount
A Black Friday deadline does one thing reliably. It moves your money earlier. You pay a deposit in November for an installation in January or February, which makes you an unsecured creditor of that company for two or three months over the quietest trading period of the year.
That is not a theoretical risk. Safestyle went into administration in 2023. Everest followed in May 2024. Andrew Wright Windows of Scotland went into administration in August 2025. Smaller failures rarely make the national press at all.
Five questions worth more than any percentage:
- How much is the deposit, who holds it and is it protected? Deposit protection comes from the installer’s consumer code, not from the industry in general.
- Is the deposit proportionate? A quarter is normal on bespoke work. Anything substantially higher, attached to a deadline, deserves an explanation.
- Who underwrites the insurance backed guarantee, and when is the policy actually issued? A guarantee from the company that fitted the windows is worth whatever the company is worth.
- Can you pay by credit card? Payments over £100 by credit card carry rights under Section 75 of the Consumer Credit Act 1974.
- Are payments staged against milestones, with a meaningful balance due on completion rather than before delivery?
We cover who actually stands behind a guarantee in double glazing guarantees and warranties, and what the industry bodies do and do not protect you from in double glazing consumer protection.
What a genuine offer looks like in 2026
A real offer adds specification. Each of these is worth having, and each comes with a condition. This is not to say of course that some offers will not be genuine, but a professional installer would accurately show the pricing differences.
Triple glazing at no extra cost
Still the best example of a genuine upgrade, but only where the system is designed to take it. The frame needs the glazing platform for a wider unit and the sash and hinges need to carry the weight. On a slim sightline aluminium system the thermal gain can be modest. Ask which glazing platform the system accepts and what the sash is rated to carry.
Toughened or laminated glass where you would otherwise get annealed
Safety glass is already required in critical locations, so this is only an upgrade for the glazing that falls outside those positions. Laminated glass also helps with security and noise, which toughened glass does not.
Compliant background ventilation included rather than charged as an extra.
Since the revised Approved Document F took effect in June 2022, a replacement window must not reduce the background ventilation that was there before, which is why trickle vents now appear where there were none. A company that includes and specifies compliant ventilation is giving you something a cheaper quote has quietly left out.
Free hardware upgrades.
Premium systems from the likes of Origin, Reynærs and Schüco offer hardware at several levels. A better handle, a higher security cylinder or a different finish is a real gain, provided it is written on the quote by product name rather than described as premium.
A waived survey fee, where a fee genuinely exists.
Most domestic installers survey free as part of the sale, so there is nothing to waive. On architectural and structural glazing work a chargeable design or site survey is normal, and that is where a waiver is worth something. If a fee is being waived, ask what it would have been and what the survey covers.
Integral blinds with bifold or sliding doors.
A desirable feature with a real price attached. They sit between the panes and cannot be serviced without replacing the sealed unit, so ask who warrants the mechanism, for how long, and what happens if one fails in year six.
A colour or finish upgrade
Non standard RAL, metallic and dual colour finishes carry genuine cost because of the extra process and the batch sizes involved. Confirm the finish specification and that the warranty on the finish is unchanged.
What all of these have in common is that they appear on the specification and can be checked against it. A percentage cannot.
Ten checks before you sign anything this November
- Ask for the same quote at the same specification dated before the offer started. If the specification has moved, the price comparison means nothing.
- Ask in writing when the offer ends and what the price will be the following week.
- Get the full specification: system name, frame depth, glazing make up, any U-value with the size and basis it was calculated at, hardware by product name, colour and finish, ventilation, cill and threshold.
- Establish whether the company manufactures or buys in finished products. It changes who controls the price, the lead time and the guarantee.
- Ask how much the deposit is, who holds it and whether it is protected.
- Ask who underwrites the insurance backed guarantee and when the policy is issued.
- Ask for the cash price and the total amount payable under finance, side by side.
- Ask what the fitting is worth and who employs the fitter.
- Look at the company’s filed accounts and how long it has traded under its current registration.
- Do nothing on the night. Take the paperwork away, sleep on it and watch what happens to the price.
A company that answers all ten without hesitation is probably worth buying from, offer or no offer.
If you are holding a quote with a deadline on it
The deadline is almost never real unless there are genuine reasons for it. For example you are having a special colour on the frames, even a different colour inside and out of specialist glass on a long lead time. Another deadline could be if your products are made abroad.
If you have a quote in front of you and a date attached to it, we will review it before you sign. That is a one hour consultation by video or telephone at £150. We read the quote against the specification and tell you what is missing, what has been priced optimistically, what the offer is actually worth and what to ask before you commit.
What we look at: whether the system suits the opening, the exposure and the building; the glazing specification and the basis of any performance figure quoted; the hardware and security specification; the deposit, payment stages and guarantee arrangements; and whether the discount exists at all.
We also connect homeowners with suppliers and installers across the UK, from volume uPVC replacement through to architectural glazing. Contact us for free, independent advice, or to arrange a quote review.
Let the Door and Window Experts do the hard work for you
In my 39 years in the industry, I’ve learned that transparency and quality are paramount. While the allure of a great deal is hard to resist, it’s essential to approach Black Friday for windows and doors with a critical eye and plenty of scepticism. You’ll find real value in genuine upgrades and clear, tangible benefits, not in flashy discounts that seem too good to be true.
Looking for the right windows and doors from the proper suppliers? Finding the best windows and doors for your project depends on several factors. We can connect you with all types of suppliers and installers around the UK to help you get the best possible windows and doors for your home. Contact us today for free, expert, impartial and independent advice.
Updated November 2026
