Do countdown timers work in a sale?

Sometimes: a countdown timer can hurry a sale along. The CMA's 2022 evidence review says limiting how long a promotion runs has been found to speed up purchases, and that the effect "likely depends on the context" (CMA, evidence review). A countdown that resets instead of ending the offer is on UK law's list of banned practices, and the CMA's guidance says most banned practices are criminal offences as well as carrying civil penalties of up to £300,000 or 10% of worldwide turnover, whichever is higher (CMA, unfair commercial practices guidance, CMA207).

Our interest, stated first. We build websites and landing pages and run paid ads, and countdown timers are often sold as a way to lift those pages' conversion rates. So the answer that would suit us is that a timer is always worth it. It is not.

This is part of our series on sale prices and urgency, checked. It reports what the evidence and the regulators say, with links to each source; it is not legal advice.

What the evidence says

The same review reports a study in which people who took timed deals "ended up, on average, with lower payoffs than those who waited" (CMA, evidence review). We found no independent study of what a timer does for a small shop's sales.

Can you use one legally?

Only if the deadline is real. Banned practice 7 in Schedule 20 of the Digital Markets, Competition and Consumers Act 2024, in force since 6 April 2025: "Falsely stating that a product will only be available for a limited time, or that it will only be available on particular terms for a limited time, in order to elicit an immediate decision and deprive consumers of sufficient opportunity or time to make an informed choice" (legislation.gov.uk). If the time limit is false and used to hurry a decision, the practice is unfair without anyone showing it changed a decision.

The CMA's example is a countdown clock after which "the offer does not in fact end, but continues and the countdown clock restarts". It adds that a true end date can still be misleading, "for example, because a substantially similar offer appears within a short period" (CMA207, as above). Its 2023 examples also include a checkout timer that restarts when the page is refreshed (CMA, open letter, March 2023).

What to do instead

• Set the end date first, and keep it. If the offer might run on, leave the clock off.
• Do not follow a timed offer with a substantially similar one.
• If a plug-in adds the timer, check whether it resets per visitor or on refresh.

The same goes for low-stock messages, the price you count down to and fees added at checkout; whether anyone enforces this against a small shop comes later in the series. A sale page follows the same landing page structure as any other, and sale pages are part of our websites work.