There is no tipping percentage that works everywhere. Expectations can differ by country, service, venue and booking arrangement. A practical approach is to check local guidance and understand the bill instead of assuming the habit you use at home applies to every trip.
Start with the destination and service
Look for current guidance from an official tourism organization or ask a reputable local contact about the particular service. Restaurant, taxi, hotel and tour practices may differ within the same destination.
For example, the Japan National Tourism Organization explains that tipping is not common for ordinary services such as restaurants, taxis and hotels. That is more useful than declaring that every person in Japan will be insulted by every possible gratuity.
A prebooked group tour or specialist service may have its own terms. Ask the provider how gratuities are handled rather than relying on a broad national stereotype.
Read the bill before adding money
A bill may contain a tax, a service charge, a stated gratuity or a suggested amount. Those terms do not necessarily mean the same thing, and a payment screen’s suggestion does not by itself establish a legal obligation.
If the wording is unclear, politely ask whether service is included and whether an additional gratuity is expected. Keep the question specific to the bill in front of you.
For a prepaid package, check the contract or confirmation. Do not assume an all-inclusive description covers every personal service, and do not assume a separately listed charge must be paid twice.
Make payment straightforward and respectful
Carry suitable small amounts of local currency if you expect to use cash. Check that a card transaction uses the amount you intended before authorizing it.
If you choose to leave a gratuity, use the method the venue accepts and avoid making a public performance of it. A clear thank-you and considerate behavior remain useful regardless of the payment custom.
Budget for the expectations relevant to your itinerary, but avoid memorizing an unsourced worldwide rate table. Current local information and a careful reading of the bill will answer more reliably than a blanket rule about a country’s wages, generosity or culture.