What is the safest house policy regarding who to card?

A common and safe house policy is to card anyone who appears to be under a generous threshold age — such as 30 or 40 — or simply to card every customer regardless of apparent age. Because people's apparent age can be misleading, setting the carding threshold well above 21 reduces the chance of missing a minor. Carding everyone removes guesswork entirely and avoids any appearance of discrimination. Servers should follow their establishment's specific carding policy, which is often stricter than the bare legal minimum.