How Banks and Couriers Use Seals to Protect Currency and Valuables

How Banks and Couriers Use Seals to Protect Currency and Valuables

Posted by Steve Diebold


Guarding our money and our valuables is part of the origin story of tamper evident seals. The practice dates back to ancient times. Ancient seals of wax are found in many stories where hot wax was used to seal valuables and the private communications of wealthy and powerful people. The wax was melted onto the seam or closure of a container or scroll. It was then marked with the impression of a “seal.” The seal impression left the private emblem or mark of a king or a wealthy person in the wax to identify the owner. The receiver could tell if the seal had been damaged or broken.

Until the modern times pay for nearly all workers was made with gold and silver coins or paper currency. For areas away from cities the “payroll” was transported to the distribution point by pack animals and later by rail or coach in sealed boxes or heavy bags. The same method of moving money was also used for transit of money to banks everywhere.

Many wild west movies depict dramatic outright theft of that money, but the more common and subtle losses came from pilfering or skimming of the money by its handlers or someone conspiring with them.

Regardless of how the money was moved, seals were used to assure it was not pilfered in transit. It was not until the early 20th century that the modern mechanical seal became common. This was the era when AC&M began making lead and wire seals for famous couriers, banks, and money handlers. Protecting money bags was a critical function of seals by then. One of the first armored trucks was brought to market the same year American Casting & Manufacturing was formed (1910). It was the origin of the modern “Security Seal” we now use in all industries.


Bank bags are still a common use for seals. Modern materials and technology have changed what a bank bag looks like, but the principle is unchanged. Currency and coins are still sealed with pull-up type bag seals. However, totes and other solid containers have replaced bags in many cases, though they still require a seal. ATM cash cassettes and the machine’s access panels are also protected by a tamper evident seal.

Bank transport containers for documents, blank checks and other valuable paper have similar sealing systems. Meanwhile, envelopes of documents or securities are transported with seals securing them. Usually, an adhesive security label or tape is used for envelopes unless the envelope already has a security adhesive closure. Reusable pouches for documents have a hole on the zipper to place a seal for verification that it was not opened.

Beyond money and securities, there are many types of valuables that require seals for tamper protection and tracking. Some of the more common are gems, fine art, legal documents, museum artifacts rare coins and other collectibles. Often these types of high value items are transported in custom packaging which has a built-in provision for a security seal.


Today’s seals for transport of high value items provide all parties (sender, carrier, receiver) with multiple aids. In addition to giving clear evidence of opening, the seal can contain serial numbers, barcodes and more -- for tracking and tracing the chain of possession. They also can be imprinted with the logo or trademark of a company both for identification as well as for promoting a brand.

There are no limits to the types of seals used in this field. AC&M produces all types of seals from lightweight to high strength, made of various materials to fit almost any need. The type of container and amount of time something will be exposed to potential tampering usually determines how much seal is needed. Things controlled internally and not exposed to persons outside the ownership chain require high tamper evidence but not high strength. Anything that could be potentially handled or accessed by outsiders (even briefly) should have a high strength seal.

The selection of a seal is highly individualized in this field and expert help and experience is important to the people who handle these things.


For over a century we have remained a leading supplier in this area. We serve companies, government agencies and organizations worldwide who need to protect high value goods in transit and storage. Banking and couriers especially rely on AC&M for quality and trusted supply of sealing technology with total discretion.

If you are responsible for securing money, valuables, and sensitive items when moved and stored, and want to know more about AC&M seals please contact us.

Our experienced experts are available during business hours in Eastern Daylight time zone by email, phone, or online chat. Our website offers comprehensive information, and the ability to order seals 24/7 from anywhere.