It is reported that passive infrastructure sharing in Thailand to deliver telecom services to end users is mandated, and it is practised in both the mobile and fixed sectors based on commercial agreements.

The Foreign Business Act (FBA) 1999 governs foreign investment in Thailand. Section 4 of the Act defines a "foreigner" as a company in which at least half of the capital or shares are held by foreigners, or a limited partnership or registered ordinary partnership with foreigners as the managing partner or manager.
According to Section 8 of the Telecommunications Business Act 2001, Type 2 licenses (telecommunications operators providing services to a specific group of customers, with or without operating their own telecommunications network) and Type 3 licenses (telecommunications operators providing their own telecommunications network for public use) cannot be granted to foreign applicants. As a result, foreign ownership in these sectors is capped at 49%.

The majority of the telecommunications infrastructure, such as the national broadband network and most submarine cable landing stations, is owned by the Government through state-owned enterprises (SOEs). The main SOEs in the telecommunications sector are TOT Public Company Limited and CAT Telecom Public Company Limited.

Thailand does not mandate functional separation for operators with significant market power (SMP) in the telecom market. However, accounting separation is mandated.

According to Section 16.2 of the Foreign Business Act (FBA) 1999, a foreigner intending to apply for a business license in Thailand must have a residence in the Kingdom or be permitted to temporarily enter the Kingdom. The Minister is empowered to issue Ministerial Regulations prescribing conditions to be observed by foreign license grantees, such as the number of foreign directors who must have a domicile or residence in the Kingdom or the period for maintaining the minimum capital in the country (Section 18).

According to Art. 5 of the Thai Foreign Business Act (FBA), when granting permission to foreigners to operate businesses under the Act, consideration must be given to both the beneficial and adverse impacts on national safety and security, the country’s economic and social development, public order, good morals, national values related to arts, culture, traditions, and customs, as well as the conservation of natural resources, energy, and the environment. Other factors include consumer protection, the size of enterprises, employment, technology transfer, and research and development.
Section 8 of the FBA outlines three categories of controlled business activities:
- List 1: Business activities that are prohibited to foreigners for specific reasons;
- List 2: Business activities concerning national safety, security, or those that affect arts, culture, traditions, customs, folklore handicrafts, natural resources, and the environment;
- List 3: Business activities in which Thai nationals are not yet prepared to compete with foreigners, such as the telecommunications sector (the Annex of the FBA provides detailed information on the businesses included in Lists 1, 2, and 3).

Foreign acquisition of a domestic, locally incorporated entity is allowed. Mergers in the telecommunication industry are regulated by the National Telecommunications Commission (NTC or the NBTC). Regarding the notification, the following circumstances are considered a merger:
(1) a licensee or its controlling shareholder mergers with other licensees (when one licensee will cease to exist);
(2) a licensee or its controlling shareholder acquires wholly or partly the assets of other licensees;
(3) a licensee or its controlling shareholder acquires more than 30% of the total voting rights of another licensee or significant control over another licensee (Clause 2(5)).
Therefore, the acquirer must file a merger review petition to the NBTC at least 60 days before the execution. The NBTC may only grant permission to the acquirer to execute a merger that does not cause market dominance. In addition, the NBTC authorises the examination of the effect of a permitted merger on competition.
Regarding the notification of the significant market power, the significant market power (SMP) is defined as operator capability that may pose a barrier to competition in the relevant market. The NBTC shall assess the non-competitive markets and the markets that have barriers to competition. Moreover, the NBTC shall identify the significant market power operators as per the requirements laid down in this notification.

Pursuant to Art. 14 of the Foreign Business Act, any initial foreign investment is subject to a minimum capital requirement of THB 2 million (approx. USD 56.000). In the case of restricted businesses (including advertising), the requirement is equivalent to 25% of the total three-year average expected annual expenditure but not less than THB 3 million (approx. USD 84.000).

Section 14 of the Patent Act 1979 (amended in 1999) stipulates that an applicant for a patent must possess one of the following qualifications: (i) be a Thai national or a juristic person with its headquarters located in Thailand; (ii) be a national of a country that is a party to a convention or international agreement on patent protection to which Thailand is also a party; (iii) be a national of a country that permits Thai nationals or juristic persons with headquarters in Thailand to apply for patents in that country; or (iv) be domiciled in, or have an industrial or commercial establishment in, Thailand or a country that is a party to a convention or international agreement on patent protection to which Thailand is also a party.
To file patents, the Ministerial Regulation No. 21 states that if the patent applicant does not reside in the Kingdom of Thailand, the applicant shall authorise an agent or patent attorney registered with the Director-General of the Department of Intellectual Property to act on his behalf (Clause 13). Moreover, the Power of Attorney (POA) shall be attached with the revenue stamp of 30 Thai Baht (around 1 USD) for each patent agent/patent attorney/application. The POA document, if not in a foreign language, must be translated into Thai (Clause 15).

Thailand is a party to the Patent Cooperation Treaty (PCT).

Thailand has a copyright regime under the law Copyright Act 1994. However, the exceptions do not follow the fair use or fair dealing model, therefore limiting the lawful use of copyrighted work by others. Art. 32 lists the exceptions, which include research or study of the work provided that such not for profit; the use for personal benefit or the family benefit including close relatives; review, accompanied by an acknowledgement of the copyright owner, among others

Copyright is not adequately enforced online in Thailand. Reported concerns include online piracy via devices and applications that enable users to stream and download unauthorised content, overly broad exceptions to technological protection measures, unauthorised collective management organisations, widespread use of unlicensed software in the private sector, a backlog of pending pharmaceutical patent applications, and cable and satellite signal theft.

Thailand has ratified the World Intellectual Property Organization (WIPO) Copyright Treaty.

Thailand has not signed the World Intellectual Property Organization (WIPO) Performances and Phonograms Treaty.

According to the Trade Secrets Act, trade secrets can be in any means or any medium which conveys a statement, story, or fact in formula, form, compilations, or assembled works, programs, methods, techniques, or processes (Section 3). The disclosure or use of trade secrets by a governmental agency that supervises the maintenance of trade secrets shall not be deemed as an infringement of rights in trade secrets in the following cases:
- When it is necessary to protect the health or safety of the public, or;
- When it is necessary for the benefit of the public, not for a commercial purpose, the governmental agency must proceed under the procedure to protect such trade secrets from being used in unfair trading activities (Section 7.2).