What is the difference between M+S and the snowflake (3PMSF) symbol?
Both markings appear on winter and all-season tires, and many drivers assume they mean the same thing. They do not: one is a claim, the other is the result of a test.
M+S: a claim about the tread
M+S, also written M&S or MS, stands for mud and snow. It describes a tread pattern with more and wider grooves than a typical summer tire. The marking is applied by the manufacturer and is not tied to a standardised snow test, so it says nothing reliable about grip on snow. Many summer-oriented SUV tires carry M+S as well.
3PMSF: a tested result
The three-peak mountain snowflake may only be used when the tire has passed a standardised snow traction test, in which it must perform measurably better than a standard reference tire. It is recognised in Europe and North America. Dedicated winter tires carry it, and so do many all-season tires. It does not cover grip on ice; in the EU a separate ice grip symbol exists for tires designed for icy conditions, such as Nordic winter tires.
What the law may require
Rules differ from country to country and change over time, so check the current rules where you drive. In Germany, for example, only tires with the Alpine symbol count as winter tires for wintry road conditions; the transition period for M+S tires made before 2018 has ended. Other countries still accept M+S markings, or have no general winter tire requirement. Our article on when to change to winter tires covers the timing.
A small example
A customer brings in four used tires marked M+S only, with 5 mm tread and production date 2019 from the DOT code. For a driver in Germany they no longer count as winter tires, whatever the tread depth. A second set marked both M+S and 3PMSF, with 6 mm tread, is suitable for winter use. (illustrative numbers)
What tire shops should record
Record the marking with every set: M+S, 3PMSF, ice grip symbol or none, next to size, load index and production date. In OrgLines you define your own attributes per product category, so season and snowflake marking can be fields on new tires, and each used tire can be recorded as its own unit with tread depth, production date, condition and photos. The customer then sees exactly what they are buying or getting back from storage.