It used to be no problem to ask airlines to “short check” your luggage or send it to a connecting city on your itinerary rather than the destination. Sometimes you need items for a meeting, but you can’t take them through security because they’re sharp objects or liquids. Or you have a long connection and want your checked bag for a shower and a change of clothes.

Airlines, though, don’t like it because they’re afraid it means you aren’t going to fly to your final destination just to where you’ve checked your bag. And that suggests you might be trying to save money on airfare with hidden city ticketing.

A flight from DC to Milwaukee via Chicago might be cheaper than flying non-stop to Chicago. So you add the connection from Chicago to Milwaukee, even though you don’t plan to take it.

That saves you money, but it violates airline rules. You may think you’re buying a seat on both the DC to Chicago and Chicago to Milwaukee flights, and you should be able to do whatever you wish with your seat (take the flight or not take the flight). The airline, though, thinks they’re selling you a ticket from DC to Milwaukee and argues that’s a different product than a flight from DC to Chicago.

The New York Times’ Ethicist said it’s ok to do. The late Supreme Court Justice Antonin Scalia did it. But there are risks,

• If you are forced to check a bag it will go to your final destination (airlines don’t like to short check) which isn’t where you’re going.
  
• If your flight is cancelled or severely delayed, the airline may want to re-route you to your final destination via a different city. (I’ve never had a problem insisting on my preferred routing.)
  
• If the airline catches you they might close your frequent flyer account (best to credit the miles to a partner program). Historically they’d only go after travel agencies issuing these sorts of tickets for the difference in fare, however Lufthansa has taken to suing customers for the money and United threatens to trash their customers’ credit.

It turns out though that you can short check bags, it’s just tough. Generally speaking airlines will let you do it on connections of 6-12 hours, and will require you to do it on 12+ hour connections (they don’t want to hold the bag that long). There are exceptions to both rules. For instance I’ve had Thai Airways keep luggage on a 14 hour overnight.

So I was interested to learn the official American Airlines policy for short-checking bags, and unsurprisingly it’s very much linked to hidden city ticketing. The policy, just updated last month, says that in order to short check a bag a customer needs:

1. A minimum of a 4 hour connection
   
2. A reason for the request

The agent has to document the reason for the request in the reservation:
BAG-CUSTOMER REQUESTED SHORT CHECK BAG ON AA FLT# DUE TO XXXXXXX

This is where agents are told a customer might reveal that they aren’t planning to take all of their flights, and agents are instructed to report the violation, and:

Since you need to offer a reason for short checking a bag, allow me to suggest:

• You’re having an affair in your layover city, and will need the bag’s contents for no more than 45 minutes.
  
• You plan to take advantage of unlimited free drinks in Main Cabin Extra and might need a change of clothes.
  
• Since American doesn’t guarantee checked baggage delivery times like Delta and Alaska do, you’re testing the airline’s checked baggage efficiency for a blog article and need as many data points as possible.

The only reason that doesn’t need a reason, according to American, is pets as baggage — pets “can always be short checked as long as the customer meets the ticketed 4 hour connection time at their mid-point city.”