For mobile phone services, all the concessions have been amended by successive government to last 25 years have gradually ended in 2015.
The private investor has to build all the required facilities and transfer them to the state before they can operate or offer services to public.
The Constitution of 1997 prompted the institutional changes when it declared that all the spectrum is a "national communication resource for public welfare".
The regulatory practice began in Thailand when the NTC was appointed by the king through the complex nomination procedure in 2005.
The inception of NTC automatically terminates and transfers all power and authority in telecommunication sector from the Post and Telegraph Department (PTD) to the newly established independent commission.
The new law dubbed the Act on Spectrum Allocation Authority, Regulatory & Control over Radio & TV Broadcast and Telecommunications of 2010 (aka NRA Act of 2010), eliminated the NTC and created a new "convergence regulator" to manage both telecommunications and broadcast in Thailand.
The new law also requires that the National Broadcasting and Telecommunications Commission which was established in 2010 as an independent regulator, must allocate all commercial spectrum licenses via auction.
In June 2014, the junta issued two new orders demanding that a) all the proceeds from spectrum auctions must be returned to the public purse and, b) all community radio stations must comply with a new junta order which would require examination and investigation of compliance before offering programming to the public.
All main mobile operators now utilise GSM/3GPP family technologies including GSM, EDGE, UMTS, and LTE.
There are three fixed-line telephone operators in Thailand: state-owned TOT Public Company Limited (now known as National Telecom (NT)), True Corporation, and TT&T (Currently name "3BB").
[3] The first fixed-line telephone system was installed in Thailand (Siam) under the Ministry of Defence in 1881, and later its operation was transferred to the Post and Telegraph Department.
TOT and CAT were corporatised in 2002–2003, and the Thai telecommunications landscape transitioned towards spectrum allocation by independent regulator.
[7] The first successful spectrum auction by the National Broadcasting and Telecommunications Commission was organised in 2012, allocating 45 MHz of IMT (2100) frequency band to three mobile phone operators.
In November, Advance Info Service and True Corporation won the 1800 MHz license in the auction which takes nearly 33 hours to complete.
The significance of this auction is the establishment of Jasmine International in the telecommunication business which didn't have a new player for many years.
Other operators include the state enterprises National Telecom (NT) with 3.45 percent market share, and mobile virtual network operators (MVNO) with 0.05 percent market share, resulting in a (HHI) of 3,421[13] On November 22, 2021, Telenor and Charoen Pokphand Group, officially announced they have agreed to explore a USD 8.6 billion merger plan between Thailand’s second and third largest telecom operators (by subscribers), True Corporation (TRUE) and Total Access Communication (DTAC) – The proposed merger is subject to regulatory approvals.
The Asia Pacific Gateway (APG), a new submarine cable, is under planning stage and is expected to be operational in Q3 2014.
Thaksin Shinawatra sold Shin Corporation, which owns 41% of Thaicom Public Company Limited.
The 2001 Act was amended in 2006 under the supervision of Prime Minister Thaksin Shinawatra to allow foreigners to own a larger holding in a Thai telecommunications business.