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What The World’s Leading Banks Looks for in Tamper-Evident Deposit Bags

February 8, 2022

While banks provide a variety of services to their clients, one of their highest priorities is cash security. Banking institutions are trusted institutions that rely on secure cash deposits and transportation for the protection of their cash and reputations. To ensure the security of cash, many banks and credit unions utilize tamper-evident deposit bags.

With the use of seals and markings, tamper evident technology protects the contents of cash bags and ensures that they arrive at their intended destination in proper condition. Many tamper-evident deposit bags include features that indicate when a bag has been opened, enabling a bank to initiate an investigation immediately. Tamper-evident bags are considered essential banking supplies by many banks and credit unions to minimize cash losses.

What makes a tamper-evident bag so crucial to your banking operations? Throughout this article, we will examine the differences between tamper evident bags and traditional cash bags. We will also examine why banks should invest in tamper evident bags, and how typical tamper evident bags are secured.


Despite the fact that traditional cash bags can be reused, they lack many of the security features that make tamper evident bags an ideal solution for banks. Most fabric cash bags can only be locked with keys or combination locks, which can be easily broken by bolt cutters. In the event that a thief uses a lockpick to defeat a lock, takes the cash inside the bag, and then relocks the bag, there is no indication that the money has been stolen.

In comparison, the safety features of tamper evident deposit bags make it incredibly difficult to hide any tampering, even if a skilled thief breaches the bag. It is possible to open tamper-evident bags by cutting the edges of the bag and then resealing it with glue or heating the plastic to melt the seams. In addition, many tamper-evident bags contain microprinting along the seams, making it difficult for a thief to match up the edges and steal cash without being noticed.

If you’re concerned that a plastic bag would not be able to withstand the rigors of cash vault and cash-in-transit (CIT) environments, think again. High-quality tamper-evident deposit bags are manufactured from resins that produce a material that is incredibly durable yet remains light so as to reduce transportation costs. Even tamper-evident bags for coins are designed to carry heavy coin deposits without breaking.


The Highest-Performing Security Bag in Banking


The future of tamper evident bank bags indicates growing demand and the continuation of evolving technology and features. What will always remain the same is purpose: the primary purpose of a tamper evident bag is to indicate if someone has opened the bag or tried to breach it. Because there are many ways a thief could try to open a cash deposit bag, most tamper evident deposit bags have multiple security features that detect different tampering methods.

The following is a list of the most common tamper evident features:

  1. Void Message

The majority of tamper-evident bags feature multiple void messages. Typically, a void message is used as part of a void seal. Upon breaking a void seal, an obvious void message is left behind to indicate the seal has been removed.

This message appears as a brightly colored pattern with the word “void” repeated, making it easy to detect so you can investigate why the bag was opened as early as possible.

  1. Freezing and Heating Attempt Detection

It is possible to defeat some tamper-evident bags by exposing them to extreme changes in temperature and then easily resealing them. Thieves who attempt to breach the bag with freezing cold air or a heat gun are likely to encounter another security feature: freezing and heating attempt detection.

With freezing and heat detection technology, temperature-sensitive ink is used to indicate if a seal has been broken by freezing or heating. In the event that the bag is exposed to excessive temperatures, a high-visibility void message will be displayed signaling that tampering has occurred.

To assist banks in conducting an efficient investigation, a number of tamper evident deposit bags are produced with different void messages for freezing and heat detection. Heat detection typically uses a red void message, while freezing detection typically uses a blue void message.

  1. Microprinting

A simple yet highly effective security feature is microprinting, which is found on many tamper-evident bags. To prevent tampering, a security border is printed along the seams of the bag with a microprinted design.

The small details of the design make it near impossible for a thief to use more covert methods of opening a bag, including cutting and resealing an edge. Even if the thief were to successfully steal cash from a bag, the microprinting would clearly indicate that the bag had been tampered with, so you can look into the matter as soon as possible.


Tamper-evident bags have rapidly become an essential part of a bank’s everyday banking supplies, alongside coin wrappers, currency straps and ATM supplies. Tamper-evident deposit bags provide banks with the assurance that their cash deposits have not been compromised at some point in the supply chain.

Following is a list of some of the main benefits of tamper-evident bags for banks:


Tamper-evident deposit bags are just as convenient to use as canvas bank bags, if not more so. The bag can be sealed simply by peeling off the adhesive strip and folding the opening shut. Upon sealing the bag, any attempt to open the bag will reveal a high-visibility void message that indicates the bag may have been tampered with.

Versatile Application

Some tamper evident bags include additional features, such as an extra pocket for checks and deposit slips. Pockets are usually perforated to simplify the sorting process for your CIT partner. If you combine your cash and check deposits, you can utilize your banking supplies budget for other purposes.

Additionally, you may order tamper-evident bags with serial numbers and barcodes so that you may scan the bags for cash and reconcile deposits with your system.

Designed for Durability

Tamper evident bags are made of high-quality plastic resins, such as polyethylene, which make the bags strong and resistant to friction. Tamper-evident bags, by virtue of their plastic construction, are also light; for banks that transport pallets of hundreds of cash bags, this can significantly reduce shipping costs.

In addition to their premium materials, tamper-evident deposit bags feature strong security seams to prevent bursting and an adhesive that will not come undone during transport.

Multiple Security Measures

Tamper-evident bags are designed with multiple security features that protect against all forms of access, including cutting, applying heat or cold, and using moisture or solvents to dissolve the adhesive seal.

The Best Tamper Evident Deposit Bags 

Cash continues to play a major role in payments, which is why tamper-evident deposit bags are an integral part of necessary banking supplies to ensure customer satisfaction and grow a bank’s reputation for security. For decades, CONTROLTEK’s tamper-evident bags have proven to be so effective that a number of the nation’s leading banks and government institutions have used them.

We offer a wide selection of tamper-evident deposit bags that will help you reduce internal theft, speed up investigations, and make cash handling easier than ever before. Get in touch with us today to learn more about how tamper evident bags can help improve your cash security.