What to Do When Your Parcel Is Too Big for an InPost Locker

The compartment door is designed to close only when nothing is in the way. Pushing a parcel in and leaning on the door can jam the mechanism with your parcel half inside, which turns a two-minute problem into a phone call to InPost. Take the parcel out, tap 'My parcel doesn't fit' and the screen cancels the attempt. Your QR code stays valid for another go at this or any other InPost locker, and nothing is charged for a failed drop-off.

Every InPost compartment is 38 cm wide and 64 cm high. Only the depth changes: 8 cm for Small, 19 cm for Medium, 41 cm for Large. So the repacking goal is depth, not overall size.

First, swap the box for a polythene mailing bag. A box holds its full depth; a bag lets soft contents settle and compress. Second, fold differently: a jumper folded in half is 20 cm, folded in thirds it is 13 cm. Third, press the air out before you seal the bag, and use a vacuum bag for puffer jackets and duvet-weight knits. Shoes lose 3 to 5 cm the moment they leave the box, which is usually the difference between Large and Medium.

• Box to mailing bag: typically saves 3 to 6 cm
• Fold in thirds rather than in half: saves a third of the depth on clothing
• Press the air out, or vacuum-pack: halves the depth of a puffer jacket
• Remove the shoe box and stuff the shoes with paper: a pair of trainers drops from Large to Medium

For Vinted and eBay labels the compartment size is chosen on the locker screen, so if a Medium would not take it, choose Large and try again; a bigger compartment costs nothing extra on a marketplace label. Only labels bought directly in the InPost app are fixed to a size (cancel and rebuy if you chose wrongly). If no Large is free, the InPost app shows live availability at nearby lockers; supermarket car-park and retail-park units have the most Large compartments, and lockers are emptied at least once a day, so the same locker is often clear by mid-morning. An InPost Shop takes the parcel over the counter if it fits InPost's limits but no compartment is free.

The largest parcel the InPost network accepts, at a locker or an InPost Shop, is 41 × 38 × 64 cm and 15 kg. Anything bigger cannot go by InPost, however it is packed. On Vinted, contact support through the app and ask for the courier to be changed to Evri, which takes parcels up to 120 cm long and 15 kg at ParcelShops, or Royal Mail, whose Medium Parcel format is 61 × 46 × 46 cm and 20 kg; Vinted also lets you request a dispatch extension while that is sorted out. On eBay the order has to go by another Simple Delivery courier (Evri, Royal Mail or DHL home collection up to 30 kg). You cannot split one order into two parcels on either marketplace: one sale is one label and one tracking number.

Measure the packed parcel at its thickest point before you leave, and compare it with 8, 19 and 41 cm. List bulky items in the right size category so the marketplace prices and labels them correctly, and if you sell a lot of coats, boots or bundles, keep Evri enabled as well as InPost so buyers can choose the courier whose limits suit the item. Our Locker Size Checker does the comparison for you from the dimensions or the item type.

A pair of boots in their box, 36 × 24 × 14 cm, sold on Vinted with InPost chosen. The seller selects Medium (19 cm) at the locker; the box plus tape is 14 cm and it fits with room to spare. Had the boots been in a larger box at 21 cm, Medium would have failed: cancel, choose Large if one is free, or take the boots out of the box, stuff them with paper, wrap them in a mailing bag at about 12 cm and go back to Medium. A pair of knee-high boots at 48 cm long and 22 cm deep in a box is over the Large depth only if you stand the box on end wrongly; laid flat, 48 cm fits the 64 cm height and 22 cm needs a Large.