Short answer
Tamper proof courier bags come in the same sizes as normal courier bags, from about 6×7 inch for small items to 20×23 inch for blankets. What makes them tamper proof is the seal: a permanent adhesive that tears the bag or leaves a mark if someone opens it. Choose the smallest size that lets the flap stick fully across the opening, because a tamper-evident seal only works when it is fully closed.
"Tamper proof" is written on almost every courier bag sold in India now. But a bag is only tamper proof if the seal actually shows when someone has opened it, and if it is the right size for the product. A big bag folded over a small product, with half the flap stuck to itself, can be opened and closed again without anyone noticing.
Tamper proof courier bag sizes and uses
| Size group | Sizes (W × L, inch) | Typical products |
|---|---|---|
| Small | 6×7, 6×8, 6.5×8 | Jewellery, watches, mobile covers, cosmetics in a box, socks |
| Medium | 8×10, 8×12, 8.5×11 | T-shirts, kids' wear, innerwear, books |
| Large | 10×12, 10×13, 10×14 | Shirts, kurtis, jeans, nightwear sets |
| Extra large | 12×14, 12×16, 12.5×15, 12.5×16 | Sarees, hoodies, suit sets, single bedsheets |
| XXL | 14×18, 20×23 | Jackets, double bedsheets, blankets, quilts, combo packs |
For an exact size, measure your packed product and add its thickness plus 1 inch to both sides, or use the polybag size calculator. The full list with cm values is on our courier bag sizes chart.
What makes a courier bag tamper proof
A normal sticky flap can be peeled back slowly and pressed down again. A tamper-evident bag is made so that this leaves proof. Look for these:
- Permanent (hot-melt) adhesive. Once pressed, the adhesive bonds into the plastic. Pulling the flap tears the bag film instead of lifting cleanly.
- Full-width adhesive strip. The glue should run edge to edge. Gaps at the corners are where a blade or a hot iron gets in.
- Opaque inner layer. Most courier bags are white or grey outside and black inside, so the product can't be seen and a cut is easy to spot.
- Printed barcode or packet code (on some marketplace bags). The code is scanned and linked to the order, so a swapped bag shows up.
Quick test before you buy in bulk
- Seal one bag and wait 10 minutes.
- Try to peel the flap back slowly. A good bag tears or stretches the film. A weak bag lifts off clean.
- Pull the side seams. They should not split before the film stretches.
- Fold the bag hard a few times. Cracking along the fold means poor or very recycled material.
If a sample fails any of these, the full order will too.
Why size matters for tamper evidence
Too big, and the extra plastic gets folded under the product. The flap may stick to only part of the opening, and the folded area can be opened from the side. Too small, and the flap gets stretched, so the adhesive touches only at the edge. In both cases the seal can't do its job.
The right size is the one where the product slides in easily, the opening lies flat and the whole adhesive strip presses down onto the bag body.
Tamper proof bags and marketplace claims
When a customer says "I got an empty packet" or "wrong product inside", the marketplace will look at your packaging and any proof you have. A tamper-evident bag that arrives intact is strong evidence that the problem didn't happen in transit after a broken seal. Many sellers also record a short packing video for each order, showing the product going in and the bag being sealed with the label visible. Check your marketplace's current claim rules in your seller panel for what proof they accept.
Read more on tamper proof packaging benefits and how it cuts fraud returns.
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Frequently asked questions
What sizes do tamper proof courier bags come in?
From about 6×7 inch for small items to 20×23 inch for blankets. Common sizes are 6×8, 8×10, 10×12, 10×14, 12×16 and 14×18 inch.
How do I know if a courier bag is really tamper proof?
Seal one, wait 10 minutes and try to peel the flap. A real tamper-evident bag tears or stretches the film instead of lifting cleanly.
Which tamper proof bag size is right for a kurti?
Most folded kurtis fit a 10×14 inch bag. Kurti sets with dupatta often need 12×14 or 12×16 inch.
Can a tamper proof courier bag be reused?
No. The adhesive is permanent and the bag tears when opened. That is how it shows tampering.
Do tamper proof bags stop all fraud?
They don’t stop it, but they make it visible. Combined with a packing video and a correct weight on the label, they make fraud claims much easier to defend.
Read next
- Courier Bag Sizes Chart: Which Size for Which ProductCourier bag sizes from 6×8 to 20×23 inch in inches and cm, with what fits in each, how to read the size and how to pick the smallest bag that seals.
- Tamper Proof Packaging Benefits for Online SellersBenefits of tamper proof packaging for online sellers: fewer empty-packet claims, proof in disputes, less pilferage, safer RTOs, more trust.
- Polybag Size Guide for India: Measure, Thickness, POD or Non-PODHow to choose a courier polybag in India: measuring your product, micron thickness, POD vs non-POD, transparent vs opaque and when to switch to a box.
- Ecommerce Packaging to Reduce Returns: What Actually WorksPackaging fixes that cut damaged, missing and wrong-item returns for Indian online sellers: tamper-evident bags, right boxes, SKU labels and videos.