We've just started exhibiting overseas, so I'm very new to the logistics of international shipping. What are some of the biggest potholes I should avoid?

Murphy's Law is alive and well in the world of international shipping. And as much as I hate to admit it, even if you've crossed every "T" and dotted every "I," sometimes Murphy strikes out of nowhere, sending your whole international shipment into a tailspin.

As the director of international operations for an exhibit-transportation firm, I've seen my share of calamities, most of which occurred for reasons outside of both my client's and my company's control. However, having a professional shipping firm on your side to handle the fallout, thinking through some of the Plan B scenarios beforehand, and working extra time and additional options into your strategy can help you sidestep or at least dig your way out of even the deepest potholes. So here are three common international-shipping issues exhibitors face, along with a few tips on how to avoid them.

➤ Airport Security: Everything from a sketchy X-ray machine to a security officer with a bad attitude can delay an international airfreight shipment. For example, we recently had a shipment flagged for additional customs screening because what officials called a "dark area" showed up on the crate X-ray. The exhibitor's crate was pulled off to the side so it could be opened and inspected by hand later that day. As a result, it missed its intended flight, and we quickly had to reroute it and rearrange the pickup schedule at the other end of its journey. Ultimately, nothing dangerous was found, and no further explanation from customs was given before the crate was sent on its merry – but now slightly delayed – way. What's more, a manual customs inspection, no matter how unnecessary it might be, costs money, so the exhibitor was also tagged with an extra inspection fee.

The lesson to be learned in this situation is to always pad your airfreight shipments with extra time and your budgets with a little extra cash. And always be sure that your crates contain exactly what the shipping documents indicate. If that customs officer uncovered discrepancies between the items listed on the documents and what he or she found inside, you can bet that "dark-area delay" would have turned into a "show-threatening incident."

➤ Permits: Depending on the country you're shipping to and the goods you're moving, you may need permits. And those permits take many days to several weeks to acquire. Plus, if your documents don't have the proper permits when your shipment is picked up by the carrier or arrives in the show's host country, the whole shebang could be sucked up into the shipping vortex – a sort of black hole that takes weeks of waiting, a frantic flurry of communication, and usually a bit of begging before it will spit out your shipment once again.

To avoid the vortex, always supply your shipping company with a commercial invoice as far in advance of the ship date as possible. As soon as it gets the invoice, it'll usually send it to its customs broker in the country to which the shipment is headed, and that broker will tell it which items need special permits. Also be sure that list of items in your shipment contains every last paper clip. We have had ordinary items, such as staplers and even empty Pez candy dispensers, confiscated by customs because they weren't on the shipping invoice or they somehow required special permits we failed to obtain.

➤ Carnet Discrepancies: A carnet is a customs document allowing tax-free and duty-free temporary export and import of goods for up to a year. Often, a carnet allows exhibitors to ship stuff into and out of the country without paying taxes. However, exhibitors can get into hot water in other countries if staffers give away or discard items that were included on their carnet.

Let's say you listed your giveaway T-shirts on your carnet, or you decided to toss an old reception desk while at the show instead of shipping it home. When customs officials check your shipment against your carnet, you'll be in big trouble because every item listed on it for the inbound trip should be present for the outbound shipment. Granted, it's usually better for a holdup to occur outbound as opposed to inbound, since you'll likely have more time to find a solution after the show. However, carnet discrepancies can result in shipment seizures, and you'll often have to pay considerable fees to get your stuff back.

Your best preventative measures are to ensure that your carnet contains only those goods that will be returning to the United States and to have a firm talk with anyone staffing your exhibit regarding what can and can't be distributed or thrown away.

As you can see, many of the snafus the can occur when shipping internationally are relatively simple in nature. However, given the myriad variables involved, including everything from tricky documentation requirements to personality quirks among customs officials, you're wise to include a little extra time and cash in your strategy and to work carefully with your transportation firm and your own staff to read and understand the fine print. That way if something still goes awry, the odds of the mishap completely derailing your exhibit-marketing plans will be greatly diminished.