There are basically three options:
1. Check excess baggage on the flight(s) you are taking.
2. Use a plain-old courier service to send the baggage.
3. Use a "Baggage Service".
Of course, there are pros and cons to each mainly with respect to cost and convenience.
The cost of checking excess baggage is usually dramatically less expensive than using a courier or baggage service. There is some evidence of this in forum chat. You can also get a good sense simply by comparing shipping costs using a courier estimator (like Fedex's) with the cost of excess baggage on your flight(s) (like WestJet's).
As a concrete real-world example, on a recent trip from YVR to OGG I checked an additional item which cost me $20 CAD. The $20 CAD + tax permitted the item to weigh up to 50 pounds or $0.40 per pound. I also took that same additional item on a regional flight to YVR. That leg cost me $0.65 CAD +tax per pound for a total of $1.18 per pound.
On the same trip I also couriered an item from the same originating town to the same destination town where I was travelling - this is an apples-to-apples comparison. The item weighed 40 pounds and cost $219.09 CAD taxes included for a cost of $5.48 per pound. There were no duties incurred as the item was imported as unaccompanied baggage (see customs and duties below).
So, in concrete numbers, the cost of couriering an item in this case was between 4x and 5x the cost of checking baggage.
I don't have concrete experience with a "Baggage Service", but the one estimate I was able to produce was approximately 20% less than the final Fedex cost. Another site for Canada to the USA offers $4.25 per pound + tax + $50 pick up fee, currency unknown. These estimates, however, are not quotations, so I can only assume that the estimates are optimistic.
There is one case where couriering excess baggage can cost less: Multi-destination journeys. For example, suppose you are going golfing in St. Bart's (do people golf there?) from London. But first, you are visiting family in Quebec, doing some business in Chicago, and going to a wedding in Florida, before going to your final destination. Your golf clubs might cost you a baggage fee on each of the four or five legs of that journey, so it could work out cheaper to just courier them to St. Bart's.
Checking excess baggage requires no pre-planning but you have to physically handle your baggage for much of the trip. This can become a pain in the following circumstances:
- you are physically unable to fit all of your baggage on an airport cart or in a single taxi cab
- you are too small/weak/tired/ill to move your baggage from the curb to/from baggage check/claim
- your itinerary involves multiple baggage claims/rechecks, complicated terminal transfers, or public transit
Shipping via courier or excess baggage service avoids baggage complications while traveling, but requires organization and logistics before and after the trip. Generally, this involves a bunch of paperwork/online form filling, scheduling a pickup or dropping off the baggage, then picking up the baggage near your destination. Altogether, takes a significant amount more time time than checking bags.
There are certain circumstances that rule out one option or another.
- Most airlines have hard limits on the size and weight of checked baggage. If the item you want to check exceeds the limit, you simply cannot take it on the plane with you. These limits are usually disclosed on the airlines' websites and are also printed on the terms and conditions of the itinerary you receive from the airline.
- Heavy, large, and odd-shaped items that are checked are more likely to end up in an unexpected place in the baggage claims area. Tracking them down can take time (think an extra hour or so). This is not a big deal if you are at the end of your final leg. However, if you have a tight connection to a flight/train/boat your excess baggage can easily cause you to miss it.
- Small planes can only carry so much baggage. If you are on a small plane at capacity with passengers, it likely has only a small amount of remaining capacity (if any) for excess baggage. Again, this is not big problem if it is the last leg of your journey. However, if you need to catch a connecting flight, you'll have to wait for the next flight of that small plane that has capacity to take your baggage. This usually means you'll miss your next flight (and the flight after that, etc).
- For couriering items, you need to have a suitable destination address to ship to. Residences are generally a poor destination address to use. It is unpredictable when the delivery will happen, so ensuring that someone will be home is difficult. There are also areas where the courier driver will not even attempt to deliver and just hold it at a depot somewhere. Specifying to hold a package at a specific courier depot is quite predictable and avoids your item from ending up in the depot other side of town/island/region by chance.
- Courier transit times are unpredictable, particularly when customs are involved or in the off-chance that the package gets miss-sorted and sent to the wrong country. So, if you are only going to be at your destination for a short period of time, it is possible that your itinerary will have you leaving before your couriered item arrives.
Customs and Duties
When you courier excess baggage you need to import your baggage as Unaccompanied Personal Effects. Make sure you fill out and attach to your shipment all the necessary paperwork otherwise you will almost certainly be charged taxes, duties, and brokerage fees.