Rules around a Thai PCB order: factory permits, environment and trade

A printed circuit board ordered from Thailand is subject to two sets of rules. The first governs the plant: its factory permission, its permitted discharges, and whether it sits in an industrial estate. The second applies once the board ships: its origin, the duty payable on arrival, and the chemical and contract requirements of US and EU buyers. All 39 plants in the MPBxChange register operate within this framework. The summary below reflects official texts as at 24 September 2026 and is general information, not legal advice.

Part 1: manufacturing in Thailand

The Factory Act and its three classes

The Factory Act B.E. 2535 (1992) empowers the Minister of Industry to divide factories into three classes according to the degree of control required. A Class 1 factory may start operating at once, a Class 2 factory must notify the authorities first, and a Class 3 factory needs a licence before it is set up.^[1] The Act also empowers the Minister to set, by ministerial regulation, standards and methods for controlling the release of waste and pollution from factory operations.^[1]

An amendment in 2019 redefined a factory as a building, place or vehicle that uses machinery of 50 horsepower or more in total, or 50 or more workers, in a type of business listed by ministerial regulation. The same amendment ended the requirement to renew factory operating licences.^[2]

The class and category of a PCB plant are set by the ministerial regulation listing factory types. The activity under which a given plant operates is stated on its factory licence or IEAT permit, which buyers can request from the plant.

Plants inside industrial estates

A plant inside an industrial estate also works under the Industrial Estate Authority of Thailand (IEAT) Act B.E. 2522 (1979). Operating a business in an estate requires a permit from the IEAT Governor. Where other laws require a licence, including the laws on factories, building control and public health, the Act vests that power in the Governor, and the Governor's permission takes the place of the other agency's.^[3] The Act also allows an industrial or commercial operator in an estate to be permitted to own land beyond limits set in other laws, and to bring in foreign skilled workers, specialists and their families beyond normal immigration limits, to work in positions approved by the IEAT Board.^[3]

In effect, section 42 allows an estate tenant to obtain mainly from the IEAT the permissions that a plant outside an estate seeks from several agencies.

Wastewater limits for metals

PCB fabrication etches and plates copper, which makes the metal effluent limits the most relevant standards. Two official sets of limits apply, depending on where the water is discharged. Water released to the environment falls under a 2016 notification of the Ministry of Natural Resources and Environment, issued under the national environmental quality law for factories, industrial estates and industrial zones, which cancelled the earlier Notification No. 3 (B.E. 2539, 1996).^[4] Water sent into an estate's central treatment plant falls under IEAT Notification No. 76/2560 (2017).^[5]

Sources: effluent to the environment, 2016 notification;^[4] discharge into an IEAT central plant, IEAT notification.^[5]

The 2016 standard sets a single value for each parameter and took effect one year after publication. Its clause 2 keeps in force, until new standards for specific factory types are issued, a Pollution Control Board notification of 20 August 1996 that names factory types allowed to discharge at values different from the cancelled No. 3 limits; the 2016 text does not restate that list or its values.^[4]

The estate permits a higher organic load, which its central plant treats, but the metal limits are identical, so copper from a PCB line must be treated inside the plant in either case. The IEAT notification requires an operator whose water does not meet the limits to build its own pre-treatment system before discharging to the central sewer.^[5] It also allows different limits where the estate's approved environmental impact assessment sets them.^[5] The Factory Act additionally empowers the Ministry of Industry to set discharge standards for factories,^[1] and the Ministry has its own effluent notification for factories, B.E. 2560 (2017), issued under that Act, which applies alongside the environmental standard above. A Department of Industrial Works summary of that notification lists the same basic values as the table, including 2.0 mg/L for copper, with different values for some named factory types.^[32]

Industrial waste

Inside estates, IEAT Notification No. 79/2554 (2011) divides industrial waste into hazardous and non-hazardous waste, requires operators to follow the Ministry of Industry's rules on disposal, and requires an annual report to the estate office by 1 March of the following year.^[6] Spent etchant, plating sludge and drilling dust are routine PCB wastes; their classification as hazardous or non-hazardous is determined under the Ministry of Industry's rules referred to in the IEAT notification.

Environmental impact assessment

The current list of projects requiring a full environmental impact assessment (EIA) is a 2023 notification of the Ministry of Natural Resources and Environment, published in the Royal Gazette in January 2024.^[7] It lists industrial estates, industrial zones under the factory law and industrial land allocation at every size, along with heavy process industries such as petrochemicals, chlor-alkali, cement, pulp, steel and non-ferrous smelting at set capacities.^[7] The list contains no entry for printed circuit board or electronics manufacture. A PCB plant therefore does not require an EIA by reason of its type alone, but a plant inside an estate operates under the estate's approved EIA, which can set its discharge limits.^[5]

BOI promotion

The Board of Investment's 2026 guide lists board-making activities under heading 4.2.4, each with a condition and an incentive group.^[8]

Printed circuit board assembly is a separate activity under heading 4.2.5.^[8] The recurring condition is that a board maker runs its own circuit trace process. The incentives for each group, and any later changes, are published on the BOI website. The BOI reports 224 projects in PCBs and electronic components, worth about 331 billion baht, from 2023 to mid-2026; these are applications for promotion, not money invested.^[9]

Part 2: buying boards made in Thailand

Country of origin

Two concepts apply: the ordinary country of origin that customs uses for marking and most additional duties, and preferential origin under a trade agreement, which determines whether a lower tariff applies.

For the United States, the country of origin is where the article was manufactured, and work done in another country must bring about a "substantial transformation" to move the origin there.^[10] US Customs and Border Protection (CBP) decides this case by case. In an April 2026 ruling, CBP found that surface-mount and through-hole assembly of components onto bare boards in the United States, followed by programming, was a substantial transformation: the product moves from a bare board to a functioning assembly.^[11] In May 2026, in a ruling on the Section 301 measures against China, CBP confirmed that the same test decides origin for those duties, and held that a headset's origin was Vietnam, where its circuit board assemblies were built by surface-mount assembly.^[12] On MPBxChange's reading, the same substantial transformation test is expected to decide origin under the 2026 Section 301 action that covers Thailand. For assembled boards, the place of assembly carries great weight. No published CBP ruling addresses a bare board etched in Thailand from imported laminate, so the position for bare boards is less settled; an importer can request a binding ruling, as the requester did in the April case.^[11]

Printed circuits fall under US tariff heading 8534.00.00, which carries a general duty rate of free.^[13] The additional duties described below therefore make up most of the US duty on a Thai board. Direct shipments account for part of the trade. In 2025 the United States took 15.5 percent of Thailand's bare-board exports by value, against 25.8 percent for China, 11.1 percent for Japan and 8.6 percent for Vietnam.^[31] A Thai board that reaches the US inside a product assembled elsewhere pays the duty set for that product and its origin.

For trade inside ASEAN, the ASEAN Trade in Goods Agreement (ATIGA) treats a good as originating if its regional value content is at least 40 percent or if all non-originating materials change tariff heading at the four-digit level, with the exporter choosing the test; product-specific rules can replace these.^[14] A separate clause deems information technology products listed in its Annex 4 to originate where they are assembled from materials covered by the same annex.^[14] The Annex 4 list published by Thai Customs includes single-sided, double-sided and multilayer printed circuits under heading 8534.^[15] Each of Thailand's other agreements has its own rules of origin, and the agreement covering the destination market applies.

US tariffs and transshipment, as at 24 September 2026

The legal basis for additional US duties on Thai goods changed twice in 2026.

After the Supreme Court decision, Executive Order 14389 ended the duties imposed under the International Emergency Economic Powers Act (IEEPA), including those under the April 2025 reciprocal tariff order as amended, and stated that it did not affect section 232 or section 301 duties.^[20] Read together, the two orders indicate that the 40 percent transshipment rate, set under the same IEEPA orders, ended with them. In July 2026 CBP described the process it was building for court-ordered refunds of IEEPA duties.^[17]

The section 301 duty rests on a USTR finding that Thailand, among other economies, does not impose and effectively enforce a ban on imports made with forced labour.^[19] Exempt products are listed by tariff code in the notice's annexes, which are published as images in the Federal Register text; printed circuits under heading 8534 are not among the exemptions.^[19]

A June 2026 executive order told US agencies to prioritise cases of misclassification, undervaluation and illegal transshipment, including investigations under the Enforce and Protect Act.^[21] In September 2026 CBP opened an advance notice of proposed rulemaking on wider supply chain disclosures aimed at goods illegally transshipped, with comments due by 1 December 2026.^[22] Thailand has run its own checks since November 2019, when it set up a watchlist of high-risk products bound for the US and required extra origin documents; a peer-reviewed study found that the watchlist did not reduce Thai exports to the US or imports from China.^[23] The declared origin should match where lamination, drilling, plating and assembly took place.

EU: RoHS and REACH

The RoHS Directive (2011/65/EU) requires that electrical and electronic equipment placed on the EU market, including cables and spare parts, does not contain the restricted substances in its Annex II.^[24] The limits apply by weight in each homogeneous material: 0.1 percent for lead, mercury, hexavalent chromium, PBB, PBDE and four phthalates (DEHP, BBP, DBP, DIBP), and 0.01 percent for cadmium.^[25] The duty to draw up the EU declaration of conformity and affix the CE marking falls on the manufacturer of the finished product.^[24] A bare board is usually treated as a component rather than finished equipment, and the EU manufacturer typically requests material data from the Thai plant for each layer: laminate, solder mask and surface finish.

Under REACH (Regulation 1907/2006), any supplier of an article containing a Candidate List substance above 0.1 percent by weight must give the recipient enough information for safe use, including at least the substance's name, and must answer a consumer's request within 45 days.^[26] Producers and importers must also notify the European Chemicals Agency when such a substance exceeds one tonne a year in their articles.^[26]

Conflict minerals

The EU Conflict Minerals Regulation (2017/821) places due diligence duties on EU importers of tin, tantalum, tungsten and gold as ores, concentrates or metals above set volume thresholds, from 1 January 2021.^[27] On that wording, an importer of finished boards falls outside its direct scope. In the United States, the SEC rule applies to companies that file reports with the SEC when these minerals are necessary to the functionality or production of a product they make or contract to make, with an annual Form SD due by 31 May.^[28] Because solder contains tin and surface finishes contain gold, customers subject to these rules request sourcing information on these metals from Thai board makers.

Drawings, NDAs and electronic signatures

Gerber files and fabrication drawings are protected in Thailand as trade secrets only if the information is not public, has commercial value because it is secret, and its controller has taken appropriate measures to keep it secret.^[29] The Trade Secrets Act B.E. 2545 (2002) treats breach of contract as a dishonest trade practice, and lets the owner seek an injunction and damages.^[29] It allows reverse engineering of a product obtained in good faith, but not where the person expressly agreed otherwise with the owner or seller.^[29] An NDA that prohibits reverse engineering, combined with confidentiality markings and need-to-know access, therefore supports both the secrecy condition and the contractual exception. The Department of Intellectual Property's English text is an unofficial translation; the Thai text governs.^[29]

Electronic signature of an NDA is legally recognised. Under the Electronic Transactions Act B.E. 2544 (2001), a message may not be denied legal effect only because it is in electronic form. Where a signature is required, an electronic method counts if it identifies the signer and shows the signer's intention and is reliable for the purpose or proven by other evidence. The Act also lists the features of a reliable electronic signature.^[30]

Sources and scope

Research date: 24 September 2026. Sources are official texts: Thai Acts and notifications in Thai from government sites, English translations published by Thai agencies, EU legislation from the EU Publications Office, US orders, notices and CBP rulings from govinfo.gov and CBP's rulings database, Thailand's customs returns to UN Comtrade, and one peer-reviewed study. The Ministry of Industry's factory classification and waste notifications, the detail of its effluent notification beyond the summary values cited, and the Hazardous Substance Act B.E. 2535 are outside the scope of this summary. The plant count is from the MPBxChange register of PCB plants in Thailand.

This summary is general information current at 24 September 2026 and does not constitute legal advice; specific cases should be checked against the current official text with professional advice.