The same box fails one carrier's international size line and clears another's by a comfortable margin.
The postal limit it misses, and the courier limit it clears
This page is about the border, not the domestic price — for nine different parts quoted coast to coast inside the US, see our auto parts shipping guide instead. Once a country enters the picture, the question stops being which US carrier is cheapest and starts being whether the box clears that country's own mail limit at all. USPS's country listing for Canada, read on pe.usps.com 2026-08-21, sets Priority Mail International's limits at a maximum weight of 66 lb, a maximum length of 79 inches, and a maximum combined length and girth of 108 inches. A boxed front bumper cover for a Honda Civic, packed to 56 × 20 × 12 in at 20 lb, clears two of those three numbers easily and misses the third by a clean 12 inches.
| Measurement | This box | USPS limit to Canada | FedEx oversize line |
|---|---|---|---|
| Length | 56 in | Clear of 79 in | Clear of 96 in |
| Length plus girth 56 + 2×(20+12) | 120 in | Over 108 in, by 12 | Under 130 in, by 10 |
| Weight | 20 lb | Clear of 66 lb | Not oversize, so the 90 lb minimum billed weight never applies |
Length alone was never the risk; a bumper cover is long but not that long. Girth is what a wide, boxy body panel adds up fast, and it is the same lesson our bike-to-Canada and bike box guides found for a completely different item: a postal product's combined-size cap is tighter than a courier's, and a box that is wide as well as long tends to hit that ceiling first. A courier account with FedEx or UPS has ten inches of room to spare on the same box that a Priority Mail International label does not.
Fluids are the other thing to check before the box gets sealed
UPS's own list of common hazardous items, read 2026-08-21, gives auto parts their own entry: a listing that “may include carburetors, gas lines, or gas tanks which may contain gasoline.” USPS's shipping restrictions page, read the same day, lists gasoline outright among the items that cannot be mailed at all. Neither carrier is describing a body panel here — both are describing whatever a part might still be carrying from the engine bay it came out of.
What needs draining
A fuel pump, a carburetor, a gas tank, anything pulled from the engine bay with fluid still in it. Drain it, wipe it dry, and let it air out before it goes anywhere near a box.
What never raises the question
A bumper cover, fender, mirror, door handle or trim panel is plastic or dry sheet metal. Nothing about a clean body part touches the fuel-residue entry above.
When in doubt, say so on the box
A part that once held fluid but has been drained is worth a plain note on the customs form — "drained and dry" — rather than leaving an inspector to guess from the part's name alone.
What the customs form actually needs
FedEx's own customs documentation page, read 2026-08-21, states the Commercial Invoice is required for any international shipment with commercial value, and it illustrates the difference between a description that works and one that doesn't with its own example: a bad description reading simply “Parts” against a good one reading “Two steel springs for woodworking machine.” The same standard applies to a car part — “car parts” alone fails it the same way “Parts” does.
Write the sentence, not the category
“One steel automobile bumper cover, aftermarket, for a 2015 Honda Civic” answers what it is, what it's made from and what it fits in one line — the same four questions FedEx's own page says a description has to answer.
Declare the used price, not the new one
A buyer paying for a used part is not paying dealer price for a new one. Declare what the part would actually sell for in its current condition, the number customs and duty are calculated against.
Find the code, don't guess it
FedEx's page does not hand over a tariff number directly; it points shippers to its own International Shipping Assist tool to work one out from the item description — the route worth using rather than a guess that turns out wrong at the border.
The forwarder leg, priced live
To Canada, the UK, Germany or Australia the whole trip can now be a single checkout booking, declaration and all. Elsewhere, most international car-part shipments move in two bookings: an ordinary domestic parcel to a US address, then a separate international booking from there, whether that is a courier's own international account or a freight forwarder. Miami carries a heavy concentration of forwarders serving Latin America and the Caribbean, so we quoted the bumper cover on that leg: Berkeley Heights, NJ to a Miami, FL ZIP, captured against production on 2026-08-21.
What we typed
used front bumper cover for a Honda Civic, boxed
Packed box
56 × 20 × 12 in
142 × 51 × 30 cm
20 lb packed (9.1 kg).
Route
Berkeley Heights, NJ 07922
to Miami, FL 33101
Both ZIPs checked live when the quote ran. This is the domestic leg only, not a border crossing.
| Carrier | Service | Price | Estimated transit |
|---|---|---|---|
| UPS | Ground | $101.87 | 5-6 business days |
| UPS | Ground Saver | $105.71 | Ground transit |
| FedEx | Ground Economy | $125.43 | 5-6 business days |
| UPS | 3 Day Select | $183.20 | 5-6 business days |
| FedEx | Ground | $183.45 | 5-6 business days |
USPS returned no rate at all for this box on this lane, even domestically — a pattern several other oversize items on this site run into as well. This is not an international price and does not get the part across a border by itself; it is the domestic leg, priced so the two-booking model has a real number attached instead of a guess. Getting the box from Miami into another country is a separate booking, either a courier's own international product or a freight forwarder.
Where these rules come from
- USPS, Individual Country Listing: Canada — the 66 lb, 79 in and 108 in Priority Mail International limits. Read 2026-08-21.
- FedEx, What is an Oversize Charge? — the 96 in length and 130 in length-and-girth thresholds and the 90 lb minimum billable weight. Read 2026-08-21.
- USPS, Shipping Restrictions & HAZMAT — gasoline listed as a prohibited item. Read 2026-08-21.
- UPS, Common Items That May Be Hazardous — the auto parts entry on carburetors, gas lines and gas tanks that may contain gasoline. Read 2026-08-21.
- FedEx, Customs documents — the Commercial Invoice requirement and the "Parts" versus "Two steel springs for woodworking machine" description example. Read 2026-08-21.
- Price: our own capture against SMKlog production checkout on 2026-08-21, from Berkeley Heights, NJ 07922. Nothing on this page is a list price or an estimate.
Every carrier and the Postal Service publish their own limits by destination country and revise them without notice. Treat the figures above as what was published on the date shown, and check the specific destination country and the specific part before booking.
Common questions
Can you ship car parts internationally?
Yes. SMKlog's checkout sells the crossing outright to Canada, the UK, Germany and Australia — live rates, customs declaration before payment — while any other destination makes the border leg a separate booking. Our own boxed bumper cover, a common eBay listing, quoted $101.87 to $183.45 for the domestic leg, Berkeley Heights, NJ to Miami, FL, captured 2026-08-21.
Does a boxed car part clear USPS's international size limit?
Depends on the part's shape more than its weight. Our bumper cover box, 56 x 20 x 12 in, clears USPS's 79-inch length cap to Canada with room to spare but misses the 108-inch length-plus-girth cap by 12 inches, read on pe.usps.com 2026-08-21. Weight was never the obstacle; it came in at 20 lb against a 66 lb ceiling.
Does the same box work through a courier account instead?
Yes, with room left over. FedEx's own oversize charge threshold, read 2026-08-21, is 130 inches of combined length and girth. Our bumper box comes to 120 inches — 10 inches under that line, the opposite of the result against USPS's tighter postal limit above.
What has to be drained before a car part ships?
Anything that has touched fuel or oil. UPS's own list of common hazardous items, read 2026-08-21, describes auto parts as an entry that "may include carburetors, gas lines, or gas tanks which may contain gasoline." USPS's shipping restrictions page separately lists gasoline itself as a flatly prohibited item. A fuel pump, carburetor or gas tank needs draining and drying first; a bumper cover, fender, mirror or trim panel never raises the question.
What does the customs paperwork need to say about the part?
A specific sentence, not a category. FedEx's own customs guidance, read 2026-08-21, contrasts a bad description, "Parts," with a good one, "Two steel springs for woodworking machine." The car-parts equivalent is something like "One steel automobile bumper cover, aftermarket, for a 2015 Honda Civic" — and the declared value should be what a buyer would actually pay used, not the price of a new one.