What's the difference between tamper evident, tamper proof and tamper resistant bags?

Tamper evident bags show clear visual proof if someone has opened them. Tamper resistant bags make opening harder but don't necessarily show evidence. 'Tamper proof' is a marketing term — in practice no bag is impossible to open, so the industry standard is tamper evident security bags with void-seal closures and sequential numbering.

Can these be used as police evidence bags?

Yes — our security bags include the sequential numbering and tear-off receipts required for chain-of-custody evidence handling, and the opaque/clear film options suit different evidence types. They're widely used by security firms, private investigators and forensic teams as well as retail loss prevention.

Are tamper evident bags reusable?

No — they're single-use by design. Once the adhesive strip is sealed, the bag can't be re-closed without showing the void message, which is the whole point of the security feature.

Are these a good alternative to lockable bags or security envelopes?

For most cash-in-transit, retail and pharmacy applications, tamper evident bags are cheaper, lighter and faster to use than lockable bags — and unlike paper security envelopes they're water resistant and tear resistant. Lockable bags suit recurring transport routes where the same bag is reused; tamper evident bags suit single-trip secure dispatch.

Do you offer custom printed or numbered tamper evident bags?

Yes — we can produce bespoke security bags with your logo, custom sequential number ranges and your choice of size and film colour. Minimum order quantities apply; use the bulk enquiry form below for a quote.

Home›Security Bags›Tamper Evident Bags

Tamper Evident Bags

Q: What is a tamper evident bag?

A tamper evident bag is a security bag with a permanent void-seal closure. Once sealed, any attempt to open the bag reveals a hidden 'VOID' or 'OPENED' message, so the recipient can immediately see if the contents have been interfered with. Each bag carries a unique sequential number and a matching tear-off receipt for chain-of-custody tracking.

Tamper evident bags, tamper proof security bags & evidence bags for cash, pharmacy, police & retail. Numbered void-seal bags in stock — free UK delivery.

Tamper-evident security bags with tear-resistant material
Sequential numbering for tracking and auditing
Available in opaque and clear styles
Different sizes to meet your needs

●In stock

Free delivery

All orders over £150

Next day delivery

Order before 2pm

Five-star rated

1,000+ UK businesses

Live chat support

Instant response

Bespoke service

Custom sizes & print

Show Dimensions:mmcminches●In stock

Image	Width	Length	Appearance	Pack Qty	SKU	Price Per Pack (Ex VAT)			Quantity
Image	Width	Length	Appearance	Pack Qty	SKU	1-4 Packs	5-9 Packs	10+ Packs	Quantity
	105mm	205mm	No Tear off Receipt	1000	BINT0121	4p	3.3pSave 18%	3.1pSave 22%
	180mm	260mm	A5 Clear Security Bag	100	BINT0106	22p	19pSave 14%	17pSave 23%
	180mm	260mm	A5 Opaque Security Bag	100	BINT0107	22p	19pSave 14%	17pSave 23%
	260mm	400mm	A4 Clear - Security Bag	100	BINT0108	27p	25pSave 7%	22pSave 19%
	260mm	400mm	A4 Opaque Security Bag	100	BINT0109	27p	25pSave 7%	22pSave 19%
	300mm	420mm	A3 Opaque Security Bag	100	BINT0140	37p	34pSave 8%	32pSave 14%
	300mm	420mm	A3 Clear Security Bag	100	BINT0141	37p	34pSave 8%	32pSave 14%

Tamper Evident Bags — Secure, Numbered, Void-Seal Security Bags

Our tamper evident bags are designed to give you visible proof if anyone has interfered with the contents in transit. Every bag uses a permanent void-seal closure that reveals a hidden "OPENED" message the moment it's lifted, along with a unique sequential number and matching tear-off receipt for full chain-of-custody tracking. They're a fast, affordable alternative to lockable bags and paper security envelopes, and the format that retail, banking, pharmacy and security professionals across the UK rely on.

What is a tamper evident bag?

A tamper evident bag (sometimes called a tamper proof bag or tamper resistant bag) is a single-use polythene security bag with a permanent adhesive strip. Once sealed, the bag can't be opened without leaving clear visual evidence — the void pattern appears across the seal and the bag itself cannot be re-closed. Each bag carries a unique number printed on both the body and the tear-off receipt, so it can be logged at dispatch and re-checked on arrival.

While "tamper proof" suggests no one can ever open the bag, in reality no bag is truly impossible to breach. The industry standard — and what every reputable supplier actually ships — is tamper evident security bags that make any breach impossible to hide.

Tamper proof security bags for every use case

Our security bags are trusted across a wide range of industries:

Cash-in-transit & banking — secure cash deposits, till lifts and end-of-day takings between branches, ATMs and the bank.
Retail loss prevention — high-value returns, in-store transfers and shrinkage investigations.
Pharmacy & medical — controlled drug transfers, prescription deliveries and patient property bags.
Legal & confidential documents — solicitor file transfers, signed contracts and confidential mail.
Courier & high-value dispatch — jewellery, electronics, precious metals and any single-trip shipment where the recipient needs to know the parcel arrived intact.

Evidence bags & police evidence bags

Our security bags double as evidence bags for police forces, private investigators, forensic teams and corporate security departments. The sequential numbering, tear-off receipt and write-on panel are exactly what's required for proper chain-of-custody evidence handling. Clear film options allow the contents to be inspected without breaking the seal, while opaque bags hide sensitive items from view in transit. Whether you need a small batch of police evidence bags for a single investigation or a regular wholesale supply, you'll find the size and format in our range above.

Security envelopes & lockable bag alternatives

If you're currently using paper security envelopes or reusable lockable bags, it's worth knowing where tamper evident bags fit:

vs security envelopes — tamper evident bags are water resistant, tear resistant and far harder to breach undetected than a paper envelope.
vs lockable bags — lockable bags suit recurring transport routes where the same bag is reused. Tamper evident bags are cheaper per use, lighter to carry and ideal for single-trip secure dispatch.

How our void-seal security bags work

Permanent void-seal closure — peel the release strip, fold and press. The seal cannot be reopened without revealing the void message.
Sequential numbering — every bag carries a unique reference number, printed on the bag and on a matching tear-off receipt.
Tear-off receipt — keep the perforated stub as your dispatch record; the recipient checks the number against the bag on arrival.
Opaque polythene film — durable, water resistant and tear resistant, so the contents stay protected as well as secure.
Write-on panel — record the date, contents, sender and recipient directly on the bag.

Choosing the right size

Pick the bag size from the pricing table above based on the largest item you'll typically send — there should be a small amount of slack for the seal to fold flat once the bag is full. As a guide: smaller sizes suit cash bags, prescriptions and documents up to A5; medium sizes cover A4 paperwork, file bundles and small valuables; larger sizes handle bulkier returns, multi-item evidence and parcels up to A3+.

UK stock & fast dispatch

All sizes are held in stock at our UK warehouse and dispatched the same working day on orders placed before 2pm. Delivery is free on orders over £150, or a flat £4.99 otherwise. For pallet quantities, custom numbering or printed branding, use the bulk enquiry form below.