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What makes a courier bag tamper proof
A tamper proof courier bag closes with a permanent hot-melt adhesive under the flap. Once the flap is pressed down, the adhesive bonds to the film. The bag cannot be peeled open and re-sealed: trying to open it tears, stretches or clouds the film, and that damage stays visible.
Strictly, the bag is tamper-evident rather than impossible to open — anyone can cut a bag. The point is that nobody can open it and close it again without leaving proof.
How it helps in a delivery dispute
When a customer says a parcel arrived opened or with items missing, the first question is whether the seal was intact. A clean, unbroken seal on delivery photos is evidence that the parcel was not opened in transit, which matters when you raise a claim with a courier or answer a marketplace complaint.
Filming the packing of high-value orders, and asking customers to photograph the parcel before opening it, makes that evidence stronger.
What to look for in a tamper proof bag
- A permanent adhesive, not a re-sealable or peel-and-stick strip meant for returns.
- Opaque film, so nobody can see what is inside the parcel.
- Film thick enough to survive a sorting hub. Courier Craft bags are 60 micron virgin LDPE, thicker than the 40–50 micron bags common in the market.
- A fully waterproof body and a seal that runs the full width of the flap.
How to seal the bag properly
- Leave enough room that the flap lies flat over the opening without being stretched.
- Peel the release liner and press the flap down firmly from the centre outwards.
- Run your fingers along the whole seal once more to remove air gaps.