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How to seal a shipping container and how many seals should a container have..

How to seal a shipping container and how many seals should a container have..??

A container seal is an integral part of a shipping container.. It is compulsory for every shipping container to have at least one seal before a shipping line allows the container to be shipped..

Container seals may come in many shapes and forms from embossed lead wire seals to plastic and metal strip seals to plastic and metal bullet seals to padlocks, all of which have been used by customers to safeguard the precious cargo that is shipped in containers..

how to seal a shipping container and types of container seals

Depending on the shipping line or the exporter and the level of safeguard required, containers may be sealed with any of the above combination of seals..

The most preferred type of seal for carriers however, is the high security bolt container seals, that meets the criteria of ISO PAS 17712..

Shipping lines have their own policies with regards to the acceptance of the different types of seals allowed by them.. For example Maersk Line, CMA-CGM, Cosco, Evergreen, MSC all have their individual policies with slight variances..

Most of the shipping lines and especially the ones that deal with USA, have established container sealing requirements under the International Ship and Port Facility Security Code (ISPS) and the Customs-Trade Partnership Against Terrorism (C-TPAT) program..

Customs authorities in most of the countries also have their own seal reporting requirements as these requirements form an important part of supply chain and national security..

Where on the container should I put the seal..??

Pic of a container door with lock rods and bullet seal..

It is imperative that a seal be present on the container and that it is put in the right place..

What would be the right place..??

Well, a container has two lock rods on each door.. The left door closes first and then the right door..

So the most effective place where the container seal needs to be put is on the right door of the shipping container as that has to be opened first..

The seal can be put either on one or both of the lock rods.. If required, you can put an additional seal(s) on the left door, but in terms of security, that really doesn’t matter unless the cargo cannot be taken out through one door..

Some containers may also have an anti-theft locking device (ATD) where a high security seal can be fixed and an optional seal fixed on the Secura Cam, located on the bottom of the third locking bar..

Where available, high security bolt seals should be placed in the “Secura Cam” position at the bottom end of the left locking bar of the right door..

So how many seals should I put on a container..??

There is no rule on how many seals you must put on a shipping container.. A container should have at least 1 seal in the right place.. A container has 4 locking rods, an optional ATD and an optional Secura Cam.. So technically there are 6 places you can put seals on a shipping container..

But whichever type of seal you put or how many ever you put, it is important to remember that a seal is not designed to eliminate theft or pilferage.. Because in most cases it is just one seal standing between the thieves and your cargo..

As you can see in below video, it is not difficult to close or break a high security bolt container seal.. The video also has information relating to evidence of tampering of the bolt seal..

But in some cases, breaking a container seal may be a nightmare as these guys will testify.. LOL..!! :):)

Anyway, the main function of the container seal is to ensure and ascertain that no one has access to the cargo from the time it has been sealed at origin till the time it has been received by the receiver..

The objective of the container seal is not just to minimize the risk of someone accessing the container and taking cargo out, but also to avoid someone putting illegal stuff into the container such as drugs, weapons of mass destruction, contraband, counterfeit etc..

For this precise reason, receivers of the cargo/container must make sure that the seal number shown on the bill of lading/manifest and the seal and seal number present on the container when they receive it are exactly the same..

A high security bolt seal with the number 123456 is different from a strip seal with the same 123456 number.. A seal with a prefix XYZ before the 123456 is different from a seal with just 123456..

A lot of the shippers/surveyors/packing warehouses at origin take photos of the container after it has been sealed, to avoid above issues..

If there is a seal or seal number discrepancy between manifest and container, the receiver should IMMEDIATELY advise the shipping line of the same and invite them for a joint survey of the container..

There are a lot of empty containers also shipped between demand and supply areas.. In certain areas of the world where the risk of stowaways are high, some of the shipping lines may also seal these empty containers so that illegal migrants, refugees, asylum seekers, human traffickers, terrorists etc do not gain access into shipping containers..

As an added security measure, empty containers may be loaded with the doors facing inwards towards other containers so there is no way to open the containers.. You may have read my previous article about the direction of containers when loaded on a ship..

So as you can see, the simple, unassuming container seal plays a very important role in global trade and global security..

Reposted with some major updates

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Hariesh Manaadiar
Hariesh Manaadiar
I am Hariesh Manaadiar, the Founder of Shipping and Freight Resource.. I have been in the dynamic shipping and freight industry for over three decades and have worked in several sectors.. I share my experiences and knowledge of the industry through this blog for those looking for help in the industry.. Stay subscribed for more free useful content about shipping, freight, maritime, logistics, supply chain and trade..


  1. Thanks for the interesting read about trying to seal a shipping container. I actually didn’t know that the seal should be put in a place that is most effective. You said it should be put on the lock rods, and I’m also interested to know if it needs to be placed at a certain distance to make it more secure.

    • Hello Taylor, glad to be of help.. Pls elaborate what you mean by “placed at a certain distance”..?? Lock rods are built at a certain distance for optimal protection and use..

  2. Assume the seal fasten in the container reads “00025046” , but the b/l and manifested reads “25046”

    does 000 missing have any effect?

    • Hi Faustine, it would still be different seal number.. There is a reason the 000 is embossed on the seal.. If all 0s are to be ignored then it wouldn’t have been embossed on the seal..

  3. In Brazil the seals on the bill of lading should match the actual seals. There are hefty fines and sometimes 3000 usd and risk of custom seizure in case of discrepancy

  4. sometimes containers are opened in the transhipment ports ,as per ISPS CODE the container opened and seals are changed without the agreement of the shipper ,after control the numbers of seals given are different from those on the bl

    • Hi Bahri, yes this is possible.. But in this case since the authorities will be opening the container as per their requirements/regulations, the onus is on the shipping line to advise the customer(s) of this inspection and also to advise them of the change in seal conditions so that the receiver can file their documents accordingly..

  5. my question on the seal discrepancy, assume the seal physically read AZXB1245780 , but on declaration say / manifest i only put number i.e 1245780 , would be a problem to be seen as seal discrepancy ?

  6. Good day Sir,

    I am a novice in shipping field. I would like to know if the seal no. in manifested Bl do not match with that on the container what would happen to the container at port of discharge. Also would like to know how to resolve the issue.

    Thanks in advance.


  7. Is there an acronym which the carrier can put on the BOL indicating the shipper secured the load and sealed it? Releasing the responsibility of the drivers hauling a load which the shipper has sealed and refuses to reopen for drivers to verify its securement. I haul dry van fak and hazmat. Sometimes the shipper has a picture of the load, but several times the picture does not show the load strapped in place. A few times after reopening the trailer the load had been strapped (half ass), but strapped. Smart enough to take a picture ..dumb enough to take it before strapped! Other times, we battle to get load securement verified from shippers. We have twice been pulled into the DOT inspection to verify hazmat load securement. Passed, but the randomness of these pull-ins are heart throbbing and shippers don’t help any! At least the ones we battle with. Thanks in advance for your answer!

  8. Hi Fidelis, if you are the consignee and you have given an express instruction to your agent NOT to open the container, and he did it, then he you can hold him liable for negligent conduct.. However, you haven’t clearly explained what the problem is.. Is the problem that there were more items in the container than what was mentioned in the packing list..??

  9. Hai Manaadiar,

    Self is orking since last 15 years in Airlines mainly in Airfreight and now want to open a freight forwarding which serves both Air and Cargo,regrading Air Freight I have plenty of experience as worked several year in Emirates Sky Cargo now as Ocean Freight Forwarding how can I excel and run a competitive freight forwarding company as others please give some of the tips.


  10. Albert,
    I work for TrakLok. So above is the answer from TrakLok. Yes the police or customs can request a generated code when they need. The point is, if we generate a code and the container is opened by police or customs, if anything is missing, we know who is responsible. Also, keep in mind, individual police or customs officers cannot just call in for a code. It would have to be given on a departmental/agency level. For instance, if a container is flagged for inspection at a point of entry by a customs officer, he can’t just call us and ask for the code. It would have to be generated and given to a predetermined representative of customs. Therefore the customs agency, not the individual officer is responsible if anything is missing. Requests come through the police department or customs agency, not individual officers.
    Another point is, if there is just a regular ISO seal on the container, police or customs will simply cut it off, whether the inspection is legitimate or not, there is no record of when the container was opened, therefore no proof that a corrupt officer stole the goods. With the GeoLok, every opening is recorded, how long the opening took, exactly where it happened, and who is responsible.

  11. Hi Manaadiar,

    I was basing my arguement on an article on seals by Traklock. I was actaully posing an arguement to them. Thus they have come up with there explanation.

    I am still not contented with their anwser since police or customs can request for a PE at any given time.

  12. “Is this not going to be abused by gullible people. For example if the same device is openned by police twice enroute to port, how then can someone determine reponsibility if a discrepancy is reported at destination. What if for a example a driver decides to do the same enrote to port of origin or even to inland destination at pod.”

    Drivers will not have the codes to open the lock. If police or customs want to inspect a load, a one time use code will be generated for that single opening only. You asked about enroute openings. The container is geofenced so that it can only open at a predetermined location at a predetermined time. If something changes the destination location or time, the client can easily change this on his computer or web-enabled mobile. Only the client can generate codes, determine locations and times for openings.
    If you’d like to know more go to and please contact us. We will be happy to discuss the features of the GeoLok in more detail.

  13. Actually, many of these seals can be “reused” or I should say can be tampered with and replaced. There are several ways to defeat these seals without leaving evidence. There are videos on YouTube on how to defeat the seals and replace them without evidence of tampering. Here are a couple.
    So these so called “high-security” seals are not really secure at all. What is needed is real physical security. In addition, if the seals are RFID enabled they can only be tracked at checkpoints and not in real-time.

  14. New technology for sure. I would like to know how this whole thing works. You said if a container with that seal is oponed by whoever, the same seal can be re-used again. Is this not going to be abused by gullible people. For example if the same device is openned by police twice enroute to port, how then can someone determine reponsibility if a discrepancy is reported at destination. What if for a example a driver decides to do the same enrote to port of origin or even to inland destination at pod.

    • Hi Albert, not sure where you are reading “You said if a container with that seal is oponed by whoever, the same seal can be re-used again.”.. Pls advise.. A seal once opened cannot be reused as the only way to open it is if it is broken..

  15. To touch base on the question posed in the article, “What would be the right place..?? A container has two lock rods on each door.. The left door closes first and then the right door.. So the effective place where the seal needs to be put is on the right door as that has to be opened first.. Either on one or both of the lock rods.. If required you can put an additional seal(s) on the left door, but that really doesnt matter unless the cargo cannot be taken out through one door..”
    The GeoLok secures both retaining bars with an armored lock. Its defeat threshhold is much longer than any ISO container seal.

  16. There is another solution to the problem of broken container seals and that is to use an armored lock. As noted above if the police or Customs break a seal for inspection in one area, then reseal it with another seal, when the cargo arrives at another port it is likely to cause a problem. With the armored lock, the police or Customs have to re lock the container with the same armored lock.
    Also combining a global real-time tracking, geofencing, and monitoring system with the armored lock will increase security against theft.
    The goal is to make the container “tamper-evident/tamper-resistant” with real-time alerting and a lock with a standoff time to allow authorities to respond to the tampering before the box is opened. Business will most likely be the implementers of this technology as they see the ROI in such devices due to increased thefts and the desire to cut insurance costs. There is a recently developed solution that brings together both aspects of physical security and real-time alerting. The GeoLok, developed by the TrakLok Corporation ( )provides better security than any other container security solution because it is not only a tracking/tamper-alerting device but it is also a armored lock with a 30 minute stand off time. For more info visit

  17. Hi ,
    In a senario where the container was police stopped, and a police seal used, container arrives at the discharge port in BRAZIL where it is established that the seal no on the b/l and the seal on the container does not match, who is responsible if there is a fine the shipping line,
    who should verify with the N76 BEFORE RELEASING B/L, forwarding agent, or TRANSPORTER

    • Hi Yunus, there could be a couple of answers depending when and where the seal was broken and reaffixed.. You mention that the police stopped the box, opened it, inspected and resealed it.. So obviously all this would have happened in SA before the container was loaded.. In this case, the bill of lading should have actually reflected the final seal (the police one) number so that there would have been no ambiguity.. I am also assuming that the clearing and/or forwarding agent and/or the shipping line/agent knew about this..?? If that was the case, then it should be a shared responsibility

      1) because the clearing agent or forwarder knew about this but chose not to amend the SI
      2) the shipping line knew about this but chose not to amend the bill of lading before release and/or amend the manifest before the cargo reached Brazil – one of the most difficult countries in the world to deal with in terms of documentation, amendments etc..

      Can you enlighten us further as to what progressed as this is an interesting case..

  18. I hve checked with SARS website for GSP – noted there are application forms to complete, viz.
    DA185.4A2 – to register as exporter and apply for GSP,(DA 46A.01 + DA46A2.02) however the GSP form is for goods produced for export to the “Community, NOrway.Switzerland, Russia or Turkey for the purpose of obtainig preferential tariff treatment.

    USA is not mentioned on this form. Now confused, if USA are part of this agreement.
    I will however, check with Chamber of COmmerce, as GSP is similar to a Certificate of Origin. DTI website suggest I contact SARS.

    Will welcome anyone who can shed some light on this issue.

    Thank you.

  19. Please advise where do you obtain the GSP(Generalised systems Preference) as a registered exporter, do you need to apply from SARS. Or do you obtain from Chamber of Commerce…. (certificate of origin).
    Importer in USA has requested exporter to issue GSP.

    Thank you.


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