Every car loses money the second you drive it off the forecourt. That's obvious. But what catches people out is that depreciation doesn't happen at a nice, even pace. There are certain moments where the value drops off a cliff, and if you're not watching for them, you'll kick yourself later. Here are five signs that it's time to sell, and what you should check before you do.

Sign #1: Your Mileage Is About to Hit a Major Bracket

Buyers think in round numbers. A car sitting at 58,000 miles on the clock will get more attention than one at 62,000, even if they're mechanically identical. The big ones to watch are 60,000 and 100,000 miles. Once you cross either of those, the perceived value takes a proper hit.

If you're creeping up on one of these milestones, run a free car valuation now and compare it to what you'd probably get in a few months. The difference might catch you off guard.

It's also good to remember that a lot of warranties and service plans are tied to mileage limits. A car that's still covered by its manufacturer warranty will always sell for more than one that's just gone past it.

Sign #2: Repair Bills Are Climbing

There's a point where the cost of keeping a car running starts to outweigh what the car is actually worth. A new clutch, a turbo replacement, or a dodgy gearbox can easily run into four figures. And here's the thing: spending £1,500 on a repair won't add £1,500 to the resale price. Most of the time, it won't add anything at all.

If you've had two or three expensive repairs in the past year, that's a pretty clear sign. The car is entering the phase where things go wrong more regularly, and selling before the next big bill lands will put you in a much better position than selling after you've already forked out the money.

Sign #3: Emissions Zone Rules Are Tightening

ULEZ in London has already caught thousands of drivers off guard, and similar clean air zones are spreading to cities like Birmingham, Bristol, and Greater Manchester. If your car doesn't meet the emissions standard for a zone you regularly drive through, daily charges will stack up quickly.

But there's a knock-on effect that's easy to overlook. Even if you never drive in those zones, the fact that they exist pushes down demand for older, higher-emission cars across the whole used market. Buyers are getting more wary of picking up a diesel or older petrol car that could end up restricted in a year or two.

If your car falls into that bracket, the longer you wait, the fewer buyers you'll have competing for it.

Sign #4: Your MOT Is Looking Risky

A clean MOT history is one of the first things private buyers look at. If your car barely scraped through its last test with a long list of advisories, or you know there's bodywork corrosion, worn suspension, or tyre issues that'll need sorting before the next one, you've got a choice to make.

Selling with a fresh MOT and no advisories is the best-case scenario. But selling a few months before a test you're not confident about can still work in your favour. You'll dodge the repair costs and the risk of a fail ending up on the car's public MOT record, which anyone can look up for free on the DVLA website.

Sign #5: A New Model Has Been Announced

When a manufacturer announces a facelift or a new generation of your car, the used market reacts fast. Buyers either hold off for the updated version or start hunting for bargains on the outgoing model, and that pushes prices down across the board.

You don't need to sell the day the press release drops. But you'll want to move before the new model actually hits showrooms. That's when the biggest drops tend to happen, because dealers will start slashing prices on older stock to clear space.

Keep an eye on car news for your make and model. Even a confirmed spy photo or a leaked spec sheet can start changing what buyers are willing to pay.

Don't Guess the Number, Check It

All five of these signs point in the same direction: find out what your car is actually worth right now. Not what you paid for it, not what a similar one sold for last year, but its current market value based on today's demand.

That number is your starting point for every decision, whether you sell privately, part-exchange, or hold on a bit longer. The worst spot to be in is finding out your car's value after it's already dropped. A quick check takes less than a minute, and it'll give you the confidence to make a smart call instead of a rushed one.