There are no legal regulations setting a tyre age limit. Heat, cold and, above all, constant wear place quite a load on tyres. Tyres increasingly lose grip over the years. Braking is worse in the wet, as is rolling resistance in the snow. These are features which ensure greater safety and therefore must not be neglected. As a rule: If your tyres are more than ten years old, they should be replaced.
However, it is not always recommended to stick to ten-year periods. Tyres can also age faster. If your tyres are frequently exposed to heat and UV radiation, then they will become porous more quickly. Continuous usage by frequent drivers shortens the service life. The average mileage of a tyre is approximately 50,000 kilometres. You determine when that figure is reached. Try to estimate it yourself: How many kilometres do you drive per year? Is your car often outside?