You can actually use a credit card if you have (I think) a trust.<p>I was watching a podcast a while back on some guys about securing baggage, it also may have been a gunnit podcast where one of the guys did this, and he registered his credit card as a firearm with the trust. All of the requirements for a firearm can also apply to a credit card (basically it has a serial), so he was able to register his &quot;firearm&quot; with his trust and take it through using the process for checking an actual firearm.