Can you drink the tap water on a European trip?
Check the local supply and any current notice. A country's reputation does not tell you whether every fountain or rural tap is drinking water.
In many European cities, refilling a bottle from the drinking-water supply is an easy way to avoid buying water throughout the day. The useful check is local: is this tap or fountain supplied with drinking water, and is there any current notice affecting it?
For example, Eau de Paris confirms that the city's drinking water, including water served in cafés and from public drinking fountains, meets the applicable quality standards. That does not turn every decorative fountain into a refill point.
Check the source of the water
Use a marked drinking-water fountain or a tap confirmed by your accommodation. Signs such as eau non potable in French or acqua non potabile in Italian mean the water is not for drinking. If you cannot establish what a tap supplies, choose another source.
Rural accommodation, private wells and mountain huts may use a different supply from a nearby town. Ask directly rather than applying a country-wide assumption. After flooding, maintenance or another disruption, follow the local water authority's notice even if the supply is normally safe.
Keep the bottle clean and avoid touching its mouth to a public spout. Refill before a long walk so that finding a fountain does not become the plan for every drink.
If the supply is uncertain
The TravelHealthPro food and water guidance recommends safe bottled or appropriately treated water where the supply is unsafe. Check the seal on bottled water. Ice and water used to wash food also matter in places where hygiene is uncertain.
Do not assume a clear mountain stream is safe to drink. If your route needs water treatment, choose a method suitable for the likely contamination and follow its instructions. A filter does not solve every chemical or microbial problem.
People preparing infant formula or managing a health condition may need specific advice; ordinary bottle-refilling guidance is not enough for those situations. Ask a qualified health professional about the trip if needed.
For an outdoor journey, combine the water plan with the weather, route and insurance checks, rather than treating it as something to solve once you are thirsty.