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With LetterAgent, the limit is clear up front: Canada-only, flat-rate Xpresspost labels with a 5 kg maximum. A parcel over that weight cannot travel on a LetterAgent label, so weigh the packed parcel before you buy the label, and if it is over 5 kg, split the contents or use a different service. A label bought for a lighter parcel does not cover a heavier one.
Carriers weigh parcels during sorting, and a parcel heavier than its label allows is flagged. What follows depends on the carrier: the parcel may be held until the sender pays the difference, it may be delivered with a charge collected from the recipient, or it may be returned to the sender. None of those outcomes is quick. A held parcel can sit for days while the carrier contacts the sender, and a recipient asked to pay an unexpected charge may refuse the parcel, which sends it back anyway. The cheapest version of this problem is the one you catch at home with a scale.
Weigh the parcel packed, not the item alone. The box, cushioning, tape, and any inner packaging all count, and for a parcel near a limit, that packing can be the difference between passing and failing. A bathroom scale works for a rough check, but it rounds coarsely at low weights. A kitchen scale is better for parcels under a few kilograms, and a parcel that reads close to the limit on any scale deserves a second weigh or lighter packing.
| Weight situation | Likely outcome | Best fix |
|---|---|---|
| Just over the label limit | Held, extra charge, or returned | Repack lighter or buy the correct label before posting |
| Over a service maximum, like 5 kg here | Cannot travel on that service at all | Split into two parcels or switch services |
| Heavy but correctly labelled | Travels normally | Check handling and box strength, since weight stresses both |
Start with the box itself. Many senders use a box far larger than the contents, then fill the gap with heavy packing material. A snug box with light cushioning, such as air pillows or crumpled paper instead of dense foam, can shave real weight. Remove duplicate packaging: an item in its own retail box inside a shipping box carries two boxes' worth of weight. If the retail box is not needed for protection, take the item out and pack it directly. Check for hidden weight too, such as a metal part, a book, or a liquid item that weighs more than it looks.
Splitting works when the contents divide cleanly, such as two items going to the same address, or a set that can travel as two parcels. Each parcel then needs its own label and tracking, and the recipient gets two deliveries, so tell them to expect both. Splitting does not help when the item itself is one heavy piece, such as a single dense object over the limit. In that case, no repacking trick changes the weight, and the honest fix is a service built for heavier parcels, with its own label and price.
Weight limits are only half the rule. Carriers also limit dimensions, and a light but very long parcel can be charged or refused on size alone. Measure the packed parcel on all three sides and check the longest side plus the girth, since some services use that combined figure. A parcel that passes on weight but fails on size faces the same held, charged, or returned outcomes, so check both numbers before you buy a label, not after the parcel is already in the system.
With LetterAgent, you get a Canada Post Xpresspost shipping label by asking your AI assistant. You get a per-label quote, approve the exact price, pay once through Stripe, and receive a label PDF. Labels are Canada-only, flat-rate Xpresspost, with a 5 kg maximum. That limit shapes several of the choices below.
Ready to ship it? Get a shipping label with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and get your label.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
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