Can You Bring a Knife on a Plane? Rules by Departure

A knife is not subject to one worldwide carry-on rule. Check every airport where you will pass security, the destination's possession/import rules, and the airline. A permission at your first checkpoint does not cover a connection.

Screening rules checked for this guide

Sources: CATSA sharp objects, UK personal items and TSA knife listings. The UK rule does not mean every blade shorter than 6 cm is allowed: the sharp/pointed condition matters too.

Checked baggage is not permission to possess a prohibited knife

CATSA identifies automatic-opening and concealed knife types as prohibited. Do not use the checked-bag column as permission to import or carry an illegal item. For an unusual knife or destination, obtain a decision from the relevant authority before packing.

Where carriage is permitted, sheath or securely wrap a sharp blade to protect baggage handlers and inspectors. Screening staff make the checkpoint decision; airline acceptance is a separate check.

A practical connection example

A traveller carrying a 5 cm knife from Canada to a non-US destination may meet CATSA's small-blade rule, yet still fail a later UK screening check if the blade is sharp or pointed. List each screening point before deciding where to pack it.

For multi-tools, identify the actual blade and mechanism rather than relying on a “travel-friendly” label. When the exact type or connection rule is unresolved, leave the item out until the authority confirms it. This guide covers the named authorities only and does not give a global legal clearance.