When selling on Amazon, businesses often hear two phrases: SIOC (Ships In Own Container) and Over Boxing. Both are ISTA 6-AMAZON.COM protocols, which serve the same goal — proving the packaging withstands the distribution journey to the customer — but contradictory approaches.
Misunderstanding this leads to two costly consequences: either trying the wrong test (results cannot be used for registration), or choosing the wrong design direction (packaging with too much material, or too thin compared to the actual journey). This article compares the two directions, based on the two ISTA 6-AMAZON.COM documents themselves and the general principles of packaging testing.
1. Core difference: who bears the impact force?
This is the only question that needs to be answered before anything else.
- Over Boxing: the product is in its retail packaging, then the whole block is placed an outer carton box (over box) has dunnage. Impact force and vibration dunnage outer box pre-absorption; Products and retail packaging receive only the remainder.
- SIOC: no outer box. The retail packaging itself is labeled as shipping and goes straight to the customer. All impact, vibration and compression forces hit the packaging directly.
In other words: Over Boxing is a test two-layer system; SIOC is the test a single class. So, two articles cannot replace each other — an Over Boxing result does not mean the retail packaging is durable enough to go it alone.
2. Compare details of the two directions
| Criteria | Over Boxing | SIOC |
|---|---|---|
| Principle | Retail packaging + outer box + dunnage | The primary retail packaging is the shipping box |
| ISTA documents | 6-AMAZON.COM Over Boxing (2018 version) | 6-AMAZON.COM-SIOC (2018 version) |
| Volume range | Light bale group (document states threshold 70 lb / 32 kg) | Divided by group: under 50 lb; 50 to less than 100 lb; 100 lb or more (parcel system limited to 150 lb / 68 kg) |
| How to group tests | A shared test string | Eight groups of Type A–H according to volume, shipping method and commodity group |
| Role of insert material | Mandatory, with specified type and thickness | There’s no outer dunnage — just the texture inside the packaging |
| Who gets evaluated? | Only product; outer box, dunnage and hazard block no being evaluated | Products and All packaging must be able to be delivered to customers |
| Additional characteristic tests | Yes hazard block (crush block simulates other heavy goods in the same box) | Yes compression clamp, Vertical compression, bridge impact, concentrated edge impact, Full rotation fall |
| Check for leaks | Not part of the main chain | 8 hour leak test with liquid cargo |
| Design consequences | Retail packaging is “shielded” — may be thinner | Retail packaging must withstand direct force — it needs to be much stronger |
The most easily underestimated detail is the “who gets rated” line. In Over Boxing, the outer box is dented, torn or the dunnage is collapsed no counted as failed — as long as the product is intact. At SIOC, it’s the opposite: if the retail packaging is opened, torn or deformed to the point that the customer does not accept it, that is a real problem, because that packaging is the package delivered to the customer.
3. About the Frustration-Free Packaging (FFP) program
FFP is one program Amazon’s is all about the unboxing experience: easy-to-open packaging, limited hard-to-recycle materials like plastic ties and hard plastic shells, and more compact size. FFP is not a separate “test”, but a design destination; To prove that the packaging meets the requirements, businesses still have to try one of two 6-AMAZON.COM protocols – depending on whether the packaging configuration is SIOC oriented or Over Boxing oriented.
To summarize in three sentences:
- SIOC and Over Boxing = two tests (proof method).
- FFP = design/experience goals (easy-to-open packaging, little excess material).
- A good SIOC design is often closer to FFP — because removing the outer box means removing a layer of material.
4. Five questions to choose the right direction
| # | Question | If you answer Yes → lean in favor |
|---|---|---|
| 1 | Is current retail packaging strong enough to withstand drops, vibrations, and compression without the need for an external box? | SIOC |
| 2 | Is the weight of the bale in the light group according to the threshold of the Over Boxing document? | Over Boxing (simpler, lower testing costs) |
| 3 | Is the product angular, thin, easily scratched, or does the brand image need to be obscured when delivered? | Over Boxing |
| 4 | Is the goal to reduce materials, reduce delivery volume, achieve a better unboxing experience? | SIOC |
| 5 | Does your business already have a set of product damage criteria and acceptable levels for packaging? | Must have — no matter which direction you choose |
Question 5 is not a technical question but a preparation question: both articles do not themselves define what “pass” means. See more Four pass/fail criteria when testing packaging to write a set of criteria before scheduling a trial.
5. Costs and risks of choosing the wrong direction
Two common mistakes and their consequences:
- Try Over Boxing and then move on to SIOC. Old results are worthless for new records. Because Over Boxing assumes there is always an outer box, its test series does not include vertical compression, spherical impact or full rotational drops like SIOC — so even the test amplitude is different. Having to start from scratch, and often having to redesign the packaging.
- Try SIOC while still in the actual box. Businesses pay more than necessary, and may be asked to design stronger packaging than is actually needed — increasing materials and long-term production costs.
In terms of cost, the SIOC test is usually longer: with atmospheric conditioning plus long vibration tests, 1 hour of standing compression, and 8 hours of leak testing with liquid cargo. See more What does the cost and time of ISTA packaging testing depend on? to know the controlling factors.
6. Frequently asked questions
Does achieving Over Boxing mean the packaging also meets SIOC?
No. The two tests measure two different configurations. REACH Over Boxing proven two-layer system activity; SIOC needs proof one class bear it yourself. These are two separate records, two separate attempts.
What if I don’t have an external box but want to be sure, how about doing both?
Just make the assignment match the actual delivery configuration. If you remove the outer box, the file is SIOC; Over Boxing is only useful when you want to compare two design options during the development phase.
Is FFP a higher level of protection than SIOC?
No. FFP is about unboxing experience and materials, not about the bearing level. It is a parallel design target, while the load bearing level is proven by the corresponding 6-AMAZON.COM protocol.
Is it possible to register in both directions for different product codes?
Yes, and many businesses do that: sensitive goods groups go towards Over Boxing, healthy goods groups go towards SIOC. It is imperative that each part number matches the actual delivery configuration and the test used.
Do test names change often?
Yes. ISTA updates its version periodically (the referenced version of both articles is 2018) and 6-AMAZON.COM was first launched in October 2014. When making an application, it should be clearly stated article name + version and review the current version before submitting.
7. Conclusion
The question “SIOC or Over Boxing” is essentially a question of packaging design, not of procedure. Three points to remember: The two articles cannot replace each other because one side has a force-absorbing outer box, the other side does not; Over Boxing only reviews products (damaged outer box is not counted as failure), also SIOC evaluates packaging as well because that packaging is delivered directly to the customer; and FFP is an experience target, not a protection level.
Before scheduling, it is necessary to finalize: actual delivery configuration (with or without an outer box), weight and outer dimensions of the package, product group, and set of product damage criteria — acceptable level for packaging. With those four things, choosing a lesson is just a matter of looking up the table.
Reference standard version: article content based on documents ISTA 6-AMAZON.COM Over Boxing (2018 version) and ISTA 6-AMAZON.COM-SIOC (2018 version).
References
The full standard should be searched and ordered directly from ISTA. Below are the public sources used for reference when compiling the article:
- ISTA 6-AMAZON.COM-SIOC, 2018 version — Ships in Own Container (SIOC) for Amazon.com Distribution System Shipment
- ISTA 6-AMAZON.COM Over Boxing, 2018 edition — Over Boxing for Amazon.com Distribution System Shipment
- ISTA — Test Procedures & Projects (current catalog, accessed September 28, 2026)
Related articles
- ISTA 6-AMAZON.COM What is SIOC? Packaging test procedure sent in the product’s own box
- What is ISTA 6-AMAZON.COM Over Boxing? Procedure for testing outer box packaging for goods sent to Amazon
- What Is the ISTA Standard? How to Choose the Right Transport Packaging Test (3A, 6-Amazon, ASTM D4169)
- ISTA Packaging Test Pass/Fail Criteria: 4 Things You Must Decide Yourself
- What Drives the Cost and Lead Time of an ISTA Packaging Test?
Discuss further
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This article is an explanatory content compiled by us for the purpose of introducing and disseminating knowledge. Article is not a translation, copy, abridgement or replacement of the parent standard, and is not reviewed, approved or sponsored by ISTA (International Safe Transit Association) or Amazon.com.
The entire content of ISTA standards is copyrighted by the International Safe Transit Association, Inc. (East Lansing, Michigan, USA) — All rights reserved. ISTA® and the ISTA logo are registered trademarks of the International Safe Transit Association, Inc.; Amazon and related trademarks are the property of their respective owners. The trademarks mentioned in the article are for indicative purposes only and do not imply any affiliation, partnership or sponsorship.
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