How to ship a Mercari item over the label limits

Before you start

• The box packed as it will ship, not the item on its own.
• A tape measure and a scale.
• A calculator, for the 139 divisor.

Steps

1. Weigh the packed box

   Mercari prepaid labels stop at 50 lb of actual weight.

   You should see an actual weight to compare against 50 lb.

2. Measure the longest side and the second-longest side

   Mercari caps a prepaid label at 34 inches on the longest side and 20 inches on the second side.

   You should see two numbers to check against 34 and 20 inches.

3. Work out the dimensional weight

   Multiply length by width by height, then divide by 139. A 24 by 18 by 16 inch box is 6,912 cubic inches, which is 49.7 lb, just inside. A 24 by 20 by 18 inch box is 8,640 cubic inches, which is 62.2 lb, outside.

   You should see a dimensional weight in pounds, whatever the scale said.

4. Compare both weights against 50 lb

   Mercari applies the 50 lb cap to actual or dimensional weight, so the larger of the two is the one that decides.

5. Set the listing to ship on your own

   Mercari states it as a listing-level choice: "When you create a listing, you can choose to use a Mercari prepaid label or ship on your own".

   You should see a listing with no prepaid label attached to it.

6. After drop-off, provide the tracking number and select I Shipped It

   On the Order Status page, enter the number from your label, then select I Shipped It.

   You should see the order marked as shipped with the number saved.

If it goes wrong

The box is under 50 lb on the scale and over it on paper

Dimensional weight is the trap on anything light and bulky. Divide the cubic inches by 139 before you assume the prepaid label fits.

Over the caps, Shipping Protection is gone anyway

Mercari Shipping Protection is excluded above 50 lb or beyond 34 inches and 20 inches, and separately requires a Mercari prepaid label. The $200 cover ($20 on a First-Class Envelope) was never available on this parcel.

The listing was set to a prepaid label before you measured

Fix the listing rather than the order. Mercari's routes for a label that is too small are all worse than choosing correctly at listing time.

What happens next

On your own label the payout still waits for the number: "If you opt to ship on your own, you'll need to provide tracking information before you can get paid." The entry is permanent, because Mercari is "unable to remove or modify tracking numbers". And a lost oversize parcel is your claim with the carrier, since Mercari's $200 protection needs a prepaid label and excludes parcels this size in any case.