TSA vs CATSA Airport Security Rules Compared (2026)
TSA and CATSA both enforce 100 ml carry-on liquid limits, but CATSA permits blades up to 6 cm while TSA bans all knives. Review 2026 security rules.
The Decision Verdict (40–60 Words)
TSA (United States) and CATSA (Canada) both enforce the 100 ml (3.4 oz) carry-on liquids cap and 100 Wh power bank limits. However, CATSA permits small knives with blades under 6 cm on domestic and non-US international flights, whereas TSA strictly prohibits all knives and blades at US airport security checkpoints.
Detailed Comparison Table
| Comparison Dimension | TSA (United States) 🇺🇸 US | CATSA (Canada) 🇨🇦 Canada |
|---|---|---|
| Carry-On Liquids Cap Identical Standard | ||
| Small Knife Blades in Carry-On Differs by Rule | ||
| Cannabis Possession at Checkpoint Differs by Rule | Federal violation (>0.3% THC) Source (TSA Cannabis) | |
| Power Bank Watt-Hour Limit Identical Standard |
Where Rules Are 100% Identical
To prevent false assumptions, the following standards are shared without difference between all compared parties:
- Carry-On Liquids Cap (100 ml / 3.4 oz)
- Power Bank Capacity (≤ 100 Wh, carry-on only)
- Checked Baggage Power Bank Ban
Key Rule Distinctions Explained
What is the rule for carry-on liquids cap?
Both agencies strictly limit liquids, aerosols, and gels in cabin baggage to containers of 100 ml (3.4 oz) or smaller packed in one clear 1-liter (1-quart) bag per passenger.
What is the rule for small knife blades in carry-on?
CATSA permits non-locking knife blades up to 6 cm (2.36 inches) on domestic Canadian flights and international flights not bound for the US. TSA bans all pocket knives regardless of blade length.
What is the rule for cannabis possession at checkpoint?
CATSA allows adult passengers to carry up to 30 grams of legal recreational cannabis on domestic flights within Canada. TSA enforces US federal law and refers any detected cannabis to law enforcement.
What is the rule for power bank watt-hour limit?
Both agencies mandate that power banks and spare lithium batteries must be packed in carry-on baggage only (strictly prohibited in checked luggage) with a 100 Wh cap without carrier pre-approval.
Traveler Recommendation & Decision Summary
Follow the stricter standard when flying transborder: TSA rules apply whenever entering the US or clearing US preclearance in Canadian airports.
Check Your Exact Items
Use our free calculators to verify watt-hours or liquids volume for your flight.
Frequently Asked Questions
Can I bring a pocket knife through security in Canada vs the US?
CATSA allows small knives with blades 6 cm (about 2.36 inches) or shorter on Canadian domestic flights. However, TSA bans all knives regardless of blade length. On flights from Canada to the US clearing US preclearance, TSA zero-tolerance knife rules apply.
Are liquid rules identical between TSA and CATSA?
Yes, TSA and CATSA enforce virtually identical liquid rules. Both require containers to be 100 ml (3.4 oz) or smaller fitted into a single transparent 1-liter (1-quart) resealable bag. Both provide exemptions for prescription medications, baby formula, and breast milk.
Can you fly with legal cannabis between the US and Canada?
No. Taking cannabis across the US-Canada international border in either direction remains strictly illegal under federal law in both countries. CATSA permits up to 30 grams on domestic Canadian flights only, while TSA treats all cannabis products as federal controlled substances subject to immediate law enforcement referral.
Do TSA and CATSA allow power banks in checked bags?
Neither agency permits power banks in checked baggage under any circumstances. Both TSA and CATSA strictly require all lithium-ion power banks and spare batteries to be transported in carry-on baggage, allowing flight attendants and crew to rapidly extinguish any unexpected thermal runaway fire in the cabin.
Official Primary Sources & Citations
- TSA Prohibited Items Verified: 2026-09-03
- CATSA What You Can Bring Verified: 2026-09-03