Design Patent Infringement: What to Do First

First, Document Everything

Before contacting the alleged infringer or taking any action, the most important thing is documenting evidence systematically - evidence with a clear, early date carries more weight than evidence gathered later:

• A sample of the suspected infringing product, along with a receipt or proof of purchase showing the date and source
• Photos of the product from every relevant angle, especially angles showing the shape, form, pattern, or surface color arrangement you suspect was copied
• Advertising or marketing materials that show or reference the suspected product
• Whatever you can identify about the manufacturer or seller
• A copy of your own design patent, to compare the overall external appearance angle by angle against the suspected product. Unlike an invention patent, which is compared against its claims, a design patent infringement comparison focuses on whether the overall visible appearance is identical or similar

What Counts as Design Patent Infringement

Under the Patent Act B.E. 2522, Section 63, only the design patent holder has the right to use the design, sell, possess for sale, offer for sale, or import into the Kingdom products embodying that design. When someone else manufactures, sells, or imports a product whose external appearance is identical or similar to the patented design without permission, that falls within infringement. The key difference from invention patents is that design patent infringement is assessed by comparing the overall external appearance - shape, form, pattern, or surface color arrangement - to determine whether it is identical or similar enough to amount to copying, rather than comparing technical claims element by element as with an invention patent.

Cease-and-Desist as a Common First Step

Patent law does not require sending a cease-and-desist letter before filing suit. In practice, though, many patentees choose to send a formal letter first, notifying the alleged infringer of the existing patent and demanding they stop. The upside is that some infringers stop immediately once formally notified, saving time and cost compared to filing suit right away. That said, sending a cease-and-desist letter is a practical strategic choice, not a legal requirement, and should be weighed case by case - in some situations, advance notice can give the alleged infringer a chance to prepare a defense or destroy evidence.

When Litigation Becomes Necessary

If a cease-and-desist letter doesn't work, or the situation is urgent, a design patent holder has the same statutory rights as an invention patent holder, since the Patent Act B.E. 2522's civil-remedy and criminal-penalty provisions cover infringement of rights under Section 63 (design patents) alongside Section 36 (invention patents):

• Injunction (temporary or permanent) - Section 77 bis lets the patentee petition the court to order the infringer to stop or refrain from the infringing act, where there is clear evidence that infringement is being or is about to be committed
• Damages - Section 77 ter empowers the court to award damages in an amount it deems appropriate, taking into account the gravity of the injury, including lost benefits and the costs necessary to enforce the patentee's rights
• Confiscation or destruction of infringing goods - Section 77 quarter requires that infringing goods in the infringer's possession be confiscated, and the court may order their destruction or other measures to prevent further distribution
• Criminal penalties - Section 85 states that anyone who commits an act under Section 36 or Section 63 without the patentee's permission is liable to imprisonment of up to 2 years, a fine of up to THB 400,000, or both. This is a separate track from the civil case, with a different process and outcome - a criminal penalty falls on the infringer, it isn't compensation paid directly to the patentee

This article does not state specific litigation timelines or court fees, since these vary case by case and fall outside what the Department of Intellectual Property publishes. Ask a lawyer or the Central Intellectual Property and International Trade Court directly for exact figures.

What the Process Generally Looks Like

Design patent infringement cases in Thailand are heard by the Central Intellectual Property and International Trade Court, the same specialized court that hears invention patent, trademark, and copyright disputes. The process generally starts with filing a complaint along with evidence; if you're seeking a temporary injunction while the case is pending, that typically requires a separate petition. The case then proceeds through trial, which includes presenting evidence comparing the accused product's external appearance against the patented design. Actual timelines and costs vary widely case by case, so a general article like this one cannot state a fixed timeframe.

Working with a Patent Agent vs. a Litigator

Responding to design patent infringement usually requires both an understanding of product design (to compare the suspected product's appearance against your patented design) and litigation expertise. Patent To You's team advises from the initial assessment and evidence-gathering stage through to coordinating with litigation counsel to pursue the matter further. That said, every case's outcome depends on its own specific facts and evidence; no result can be guaranteed in advance for any case.

Frequently Asked Questions