M+S and the snowflake symbol are not the same thing, and the difference is that one of them has been tested. Plenty of all-season and even some summer-biased tyres carry M+S. Far fewer carry the snowflake. If you are choosing tyres for genuine winter use, or driving to the Alps, that distinction is the one that matters.
What the snowflake actually certifies
The three-peak mountain snowflake symbol shows a small mountain outline with a snowflake inside it. A tyre may only carry it if it has passed a defined snow traction test, measuring acceleration performance on packed snow against a reference tyre.
It is a pass or fail. That makes it a meaningful, comparable marking rather than a marketing description, and it is why regulators reference it.
Why M+S is weaker
M+S stands for mud and snow. Crucially, there is no performance test behind it in the way there is for the snowflake. It has historically been applied on the basis of tread geometry, which means a manufacturer can mark a tyre M+S because of how it looks rather than how it performs in snow.
In practice many all-season tyres carry both markings, which is the combination you want. A tyre carrying M+S alone tells you comparatively little about its cold-weather grip. Our guide to all-season tyres covers where that category genuinely helps in a UK winter.
Does it matter in the UK?
There is no UK legal requirement to fit winter or snowflake-marked tyres at any time of year. UK law sets a minimum tread depth of 1.6mm across the central three-quarters of the tread and requires tyres to be fit for purpose and free from defects, which is set out on GOV.UK. Nothing in that mandates a seasonal tyre.
Where it matters is performance rather than legality. Winter and snowflake-marked tyres use compounds that stay flexible at low temperatures, so their advantage appears in the cold and wet as well as in snow. Whether that is worth it for your mileage and location is the question we work through in are winter tyres worth it in the UK.
Driving in Europe is where it counts
Several European countries operate seasonal requirements or conditional rules requiring suitable winter equipment in wintry conditions, and the trend has been to specify the snowflake symbol rather than accept M+S alone. Requirements vary by country and can change, so the practical advice is to check the rules for each country on your route before you travel rather than assume.
We cover the general approach in winter tyre law in Europe and the wider pre-trip checks in driving abroad tyre rules.
Checking what you already have
Have a look at your sidewalls. Many drivers on all-season tyres already have the snowflake and do not know it, and some who believe they have winter tyres have M+S-only rubber. Check all four, because a car that has had tyres replaced one at a time can easily end up with a mixture, which gives you neither consistent behaviour nor a clean answer at a border.
If you want a second opinion, our fitters check condition, tread and markings as a matter of course. We can also supply and fit winter or all-season tyres at your home or work. Book a check.
