How Long to Keep Drawings: Checking the 10-Year Rule Against the Statute

Hello, this is Ryuta Hamamoto from TIMEWELL.

"How long do we have to keep drawings?" Plenty of companies cannot answer that consistently in-house.

Search and you get pages saying five years and pages saying ten, neither citing anything. Half the results are about construction, where design documents run fifteen. You are looking for manufacturing and you get the Architects Act.

This piece works from the statutes. The conclusion first: no Japanese law sets a retention period for drawings as such. So where does the ten years come from? That is where we start.

The short version:

• Drawings have no statutory period. The ten years is worked backwards from the Product Liability Act
• That Act extinguishes claims ten years from delivery, with a separate five-year limb from discovery for personal injury
• Transaction records run two years under subcontracting law; books run seven under tax law
• The bases and the start dates all differ, so a register by document type is the only workable answer
• The fifteen years you keep seeing is construction. It has nothing to do with manufacturing

No statute covers drawings themselves

Let me be clear about this first.

The Companies Act, the Corporation Tax Act, the Product Liability Act, the subcontracting transaction law. None of them contains a clause saying "manufacturing drawings shall be retained for X years." What carries a retention obligation is books and records, and records relating to transactions — and drawings do not automatically fall inside those definitions.

So why does everyone say ten? Because it is worked backwards from the Product Liability Act.

What Article 5 says

Here is Article 5 of Japan's Product Liability Act¹.

Article 5. The right to claim damages under Article 3 shall be extinguished by prescription in the following cases. (i) Where it is not exercised within three years from the time the injured party or their legal representative becomes aware of the damage and the party liable for the damages. (ii) Where ten years have elapsed from the time the manufacturer delivered the product. (2) For the right to claim damages where life or body has been harmed, "three years" in item (i) of the preceding paragraph shall read "five years."

Two things follow.

First: ten years from delivery. Your exposure on a product you made ends ten years after you handed it over. So for that period you need to be able to explain what the design was. Keeping drawings for ten years maps onto this.

Second: five years from discovery, for personal injury. If an incident occurs within that ten-year window and the injured party subsequently learns of the damage and the liable party, they then have five years. Which means the moment you are actually asked to explain can fall later than ten years.

The reading I take from that is that ten years from delivery is a floor, and some products deserve longer. A product still supported with spare parts needs its drawings throughout that support. Capital equipment with a long service life needs longer still.

Two years for transactions, seven for books

Separately from drawings, transaction documents carry obligations with clear periods.

Subcontracting transaction law. Documents the buyer must create and retain are kept for two years. Prescribed content includes the inspection completion date, the treatment of rejected goods, and the substance and reason where a change or rework was required².

Note that the amendment effective 1 January 2026 added dies and tooling other than metal moulds to the scope of manufacturing subcontracting — wooden patterns, workholding fixtures, forming dies, and dedicated special tooling³. If you outsource fixture manufacture, check whether your transactions are now covered.

Corporation Tax Act. Books and records are retained for seven years as a rule⁴. Quotations, purchase orders, contracts, and delivery notes fall here. The clock starts the day after the filing deadline for the fiscal year's tax return.

Companies Act. Accounting books and important materials relating to the business run ten years.

The thing to watch is that the same "drawing" lands in different boxes depending on its role. A drawing attached to a quotation sent to a customer can form part of a transaction document. An internal design drawing does not. You have to decide the basis, the period, and the start date per document type.

The fifteen years in your search results is construction

Search for drawing retention in Japanese and fifteen years jumps out. That is the retention period for design documents under the Architects Act, and it has nothing to do with manufacturing drawings.

The reason it bleeds in is that the same word covers both fields. Narrow the search to mechanical or production drawings, or work backwards from the statute.

The same goes for public works design change guidelines, which are aimed at civil engineering clients.

Start dates and retrievability cause more trouble than the period

Now the practical part. Two things trip people up even after the period is set.

First, the start date. When is "delivery"? For a part you have been making to the same drawing for years, it is ten years from the last shipment. Which means the period keeps extending as long as production continues. Counting from the date the drawing was created is not enough.

Second — and I think this is the real issue — can you find it?

Retaining something to policy is worthless if it does not surface when you need it. Someone asks for a drawing from ten years ago and nobody knows which server, which folder, which revision. It exists on paper, in one of those boxes. Holding a document and being able to use it as evidence are different things.

And the drawings that are hardest to find tend to be wanted in the most serious circumstances: a customer defect claim, a recall investigation, litigation. To avoid saying "it should be here somewhere" in that moment, I would fix retrievability before fine-tuning the period.

Put it in a register and route destruction through approval

The practical answer is a retention register.

For each drawing type, list the legal basis, the period, the start date, the scheduled destruction date, and the approver. Types might break down like this:

• Product drawings (for products delivered to customers)
• Part and machining drawings
• Fixture and tooling drawings
• Inspection drawings and procedures
• Drawings attached to quotations
• Customer-supplied drawings

Customer-supplied drawings need particular care. The customer owns them, so beyond any retention period there may be an obligation to return or destroy. NDAs frequently carry a clause requiring return or destruction after termination, with certification. You cannot quietly hold on to something you were lent.

Once the register exists, route destruction through approval. If an individual can bin things on their own judgement, there is no way to distinguish a justified disposal from a tidy-up. An approval column in the register is the evidence.

The register is also what you hand over when a customer quality audit or an ISO 9001 assessment asks how document retention is managed.

The register

There is a drawing retention register using the classification above: drawing type, legal basis, period, start date, scheduled destruction date, and approval. Return and destruction of customer-supplied drawings has its own block.

You can add types to suit your product mix. The download link is at the end of this article.

Building the "findable" part

Let me be straight about where we fit.

Storage itself is not our territory. That is drawing management systems, PDM and PLM. A file server works if the rules are followed.

Where we can help is making things findable. Retrieving a ten-year-old drawing not by number but by geometry, by the product it went into, by the objection raised at the time. Our enterprise AI, ZEROCK, can be used to search across drawings and their surrounding context wherever they have ended up.

But again: settle the periods and the register first. Tuning search before you have decided what to keep leaves the search with no defined target.

There is more on the systems side in drawing management, PLM and PDM and on paper in digitising paper drawings.

In summary

• No statute sets a retention period for drawings. Ten years is worked backwards from product liability
• Article 5 says ten years from delivery; personal injury adds five years from discovery, so you can be asked to explain later than ten years out
• Subcontracting documents run two years, books seven under tax law, accounting books ten under the Companies Act
• The fifteen years is construction design documents. Not applicable to manufacturing
• The start date is the last shipment. Ongoing production keeps extending it
• Retrievability causes more practical trouble than the period does
• Build a register by type and route destruction through approval. Customer-supplied drawings may carry return or destruction obligations

This is not legal advice; check individual questions with your counsel. If the topic is making drawings findable, get in touch.

References

Footnotes

1. Product Liability Act (Act No. 85 of 1994), Article 5 (e-Gov, Japanese). The provision is quoted from the Act ↩

2. Leaflet on the Act on Ensuring Appropriate Transactions in Manufacturing Subcontracting (Japan Fair Trade Commission, August 2025, Japanese). The document creation and retention obligation, the two-year period, and the prescribed content come from this material ↩

3. Key points of the amendment (SME Agency, briefing material, 14 October 2025, Japanese). The addition of dies and tooling other than metal moulds, effective 1 January 2026, comes from this material ↩

4. Corporation Tax Act Enforcement Regulations, Article 59 (e-Gov, Japanese). Books and records are retained for seven years as a rule, starting the day after the filing deadline for the fiscal year. Companies Act Article 432(2) sets ten years for accounting books and important materials relating to the business ↩