The right security seal depends on what you're securing, the level of security required, your operating environment, and any applicable regulatory or customer requirements. There is no single "best" seal for every application.
When selecting a security seal, consider:
At Cambridge Security Seals, we help customers select security seals every day based on their application, operating environment, and security objectives. In many cases, a brief conversation is all that's needed to recommend a solution that balances security, ease of use, compliance, and cost.
If you're unsure which seal is right for your application, our team can help you evaluate your requirements and recommend an appropriate solution.
At Cambridge Security Seals, we begin by understanding your application, quantity, operating environment, compliance requirements, and customization needs before recommending a solution.
A lock is designed to delay or prevent unauthorized access, while a security seal is designed to provide visible evidence if unauthorized access has occurred. Although many security seals are difficult to remove without specialized tools, no security seal is intended to be an impenetrable physical barrier.
Think of a security seal as a witness rather than a barrier. Its purpose is to show whether a shipment, container, tote, valve, cart, or other secured asset has been opened or tampered with.
When used with serialized numbering, documented inspections, and chain-of-custody procedures, security seals help organizations detect unauthorized access, strengthen accountability, and support investigations when security incidents occur.
At Cambridge Security Seals, we've found that the most effective security programs combine tamper-evident products with clear procedures and employee accountability. Strong security depends not only on the seal itself, but on how security processes are managed throughout the supply chain.
A tamper-evident security seal is a device designed to show visible evidence of unauthorized access or tampering. Security seals help protect cargo, trailers, containers, totes, and other assets while maintaining chain of custody.
Chain of custody is the documented process of recording who had possession of or access to a shipment, container, trailer, package, or other secured asset throughout its journey. It helps organizations maintain accountability by documenting each transfer of responsibility from origin to destination.
Chain-of-custody procedures often include:
When combined with tamper-evident security seals, chain-of-custody documentation helps organizations identify where unauthorized access may have occurred and strengthens overall supply chain security.
Security seals do not physically prevent cargo theft, but they help deter opportunistic theft, provide visible evidence of unauthorized access, and strengthen accountability throughout the supply chain.
Thieves avoid entrances with highly visible physical barriers and security seals due to psychological deterrents like the fear of being seen, perceived difficulty (“Don’t Even Try”, and dread of guaranteed identification. These visible cues trigger an instinctive risk calculation, referred to as CPTED (Crime Prevention Through Environmental Design).
A security seal may have been tampered with if it shows visible damage, no longer matches its recorded identification number, or displays evidence that it has been opened, altered, or replaced. Every seal should be inspected before accepting or transferring a shipment.
Common signs of tampering:
For plastic, bolt, and cable security seals
For tamper-evident labels and security tape
If any of these signs are present, the shipment or package should be inspected in accordance with your organization's security procedures before it is accepted or distributed.
Regular inspections, seal number verification, and documented chain-of-custody procedures are essential components of an effective supply chain security program.
If you're unsure what to look for, the Cambridge Security Seals team can guide you in inspecting the specific security seal, tamper-evident label, or security tape used in your application.
Tamper-evident security seals are designed to make unauthorized opening visible, but no security product is completely tamper-proof. The effectiveness of a seal depends on its design, correct application, and the environment in which it is used. For higher-risk applications, organizations often combine tamper-evident seals with seal number verification, chain-of-custody procedures, access controls, and other security measures as part of a layered security strategy.
International Organization for Standardization 17712 is an international standard that establishes requirements for high-security seals used in cargo transportation.
ISO 17712-certified high-security bolt seals are commonly required or specified for ocean shipping containers, international freight, and cross-border transportation where maintaining container integrity is critical. They are also widely used by organizations participating in supply chain security programs such as the Customs Trade Partnership Against Terrorism (C-TPAT) and by companies that require documented chain-of-custody procedures.
High-security bolt seals are commonly used for:
An ISO 17712-certified bolt seal helps verify that a container has not been opened during transit. Each seal carries a unique identification number that can be recorded and verified at every transfer point, helping organizations detect unauthorized access and support supply chain security.
While an ISO 17712-certified seal is an important security control, it is most effective when used as part of a layered security strategy that includes seal number verification, documented inspection procedures, chain-of-custody records, employee training, and cargo monitoring.
If you're unsure whether your shipments require an ISO 17712-certified high-security seal, Cambridge Security Seals can help you determine the appropriate solution based on your transportation mode, customer requirements, and security program.
If you're shipping ocean containers internationally, participating in C-TPAT, or moving high-value cargo across borders, an ISO 17712-certified bolt seal is often the appropriate choice.
Both bolt seals and cable seals provide a high level of security, and each seal type is designed for a different application.
Bolt seals are commonly used on ocean containers, trailers, and cross-border shipments where ISO 17712 compliance may be required. They provide a strong visual deterrent and typically require a bolt cutter for removal.
Cable seals are ideal when greater flexibility is needed, for instance, for applications with varying latch sizes or multiple locking points. Depending on the diameter, they provide an equally high level of security and typically require a cable cutter for removal.
Customs Trade Partnership Against Terrorism (C-TPAT) is a voluntary U.S. Customs and Border Protection program that promotes supply chain security and risk reduction.
Yes. Cambridge Security Seals offers three C-TPAT compliant security seals that carry the "High-Security Seal" designation as defined by ISO 17712:
These seals meet the standards of the Customs-Trade Partnership Against Terrorism (C-TPAT) program, a voluntary government-business initiative to improve global supply chain security. All three are designed to provide tamper-evident protection for international shipments and regulated cargo.
Yes. Cambridge Security Seals offers industry-leading customization options across nearly every product line. Customizable features include:
CSS also offers an innovative custom seal builder that guides you through selecting your seal type, configuring specifications, personalizing your imprint, and placing your order.
Many security seals can be customized with company logos, barcodes, sequential numbering, QR codes, custom text, and color options. Customization can strengthen security, improve traceability, support operational processes, and make it easier to identify authorized seals in the field.
Whether your objective is brand recognition, inventory control, compliance, or chain-of-custody management, customized seals can be designed to meet the specific needs of your organization.