Postal size is based on the sealed item's external measurements and weight. Packaging names and product dimensions are not enough to select a postage format.
Compare packet and parcelFinish the package, then measure its greatest length, width and thickness or depth. Include bulges, handles, tubes, padding and any rigid section that changes the outer shape.
Check letter, large envelope, packet and parcel limits against the same packed item. It must satisfy every relevant limit for a format; exceeding one means checking the next eligible option.
A format accepted for one domestic service may have different availability or limits internationally or under express and registered products. Confirm both the format and selected service.
Understating weight or dimensions can cause delay, payment requests or return. If an item is close to a limit, repack it safely or buy the next valid format rather than relying on measurement tolerance.
Rules, availability and rates can change. Confirm the live details before buying postage.
Measure the sealed parcel at its longest external points and weigh it with all packaging. Apply the current service rules.
Only if the packed mailer meets every letter limit and content rule; many padded items fall into a larger format.
Choose an eligible larger service or another carrier before posting. Do not buy a smaller format using reduced measurements.
Use the packed item, exact destination and evidence you need to compare a valid current option.
Compare packet and parcel