Before you fly
Firearms must be transported unloaded, in a locked hard-sided case, inside checked baggage. TSA regulations require you to declare the firearm at the airline counter and complete a signed declaration card that goes inside the case. Only you retain the key or combination — TSA-approved locks are not required for firearm cases and are actually discouraged.
Ammunition must be in original manufacturer packaging or a purpose-built container (plastic ammo box, MTM case) and can be packed in the same checked bag as the firearm on most US carriers. Airlines cap ammunition weight — typically 11 lbs per passenger — and some require a separate declaration form.
Check your airline's firearms page 48 hours before travel. Hawaiian, Alaska, Southwest, Delta, United, and American all publish specific instructions and they change without much notice.
At the mainland airport
Arrive 30–45 minutes earlier than usual. Tell the agent at check-in that you are declaring a firearm; do not use the kiosk. The agent will hand you the declaration card, watch you place it inside the case, watch you lock the case, and then route the bag to TSA for inspection.
TSA may call you back to unlock the case for inspection. Stay near the counter until your bag clears — do not head to security until an agent releases you.
Arrival and registration in Hawaii
Non-residents bringing a firearm into Hawaii must register it in person at the county police station within 5 days of arrival. Bring your photo ID, your Hawaii permit (or a copy of your application if it's pending), and the firearm itself — unloaded and cased — to the appointment.
Registration is free but must be repeated for each firearm you bring. Honolulu Police Department requires an online appointment through their firearms unit; neighbor-island counties typically accept walk-ins during posted hours.
Keep the registration receipt on you for the duration of your trip. Local law enforcement can and does ask for it during traffic stops or at range check-ins.
Inter-island travel
Flying between Hawaiian islands with a firearm follows the same TSA declaration process as arriving from the mainland — unloaded, hard case, checked, declared at the counter. There is no exemption because you're already 'in Hawaii.'
Keep your county registration paperwork accessible on the receiving island. If you're moving between counties (e.g., Honolulu to Maui) for more than a short visit, the receiving county's police may want to see your paperwork.
What not to do
Do not carry concealed inside airport terminals past security. Federal sensitive-place rules apply and Hawaii enforces them aggressively.
Do not ship your firearm to your hotel. Hotels are not FFLs and cannot legally accept a firearm transfer. If you need to pre-position a firearm, ship it to a Hawaii FFL for pickup on arrival.
Do not carry into state or federal parks, schools, government buildings, bars, or any posted private property. Hawaii's sensitive-places list is broader than most mainland states.