On September 21, 1977, the Company was incorporated as a limited company under the Civil and Commercial Code named “Siam United Services Co., Ltd.” with an authorized capital of Baht 5 million to render oil transportation services by tankers to the large oil traders at that time such as Esso (Thailand) Co., Ltd., The Shell Company of Thailand Ltd., and Caltex Oil (Thailand) Co., Ltd.

In 1985, the Company raised its paid-up capital from Baht 5 million to Baht 75 million, and on December 25, 1985, the Company was permitted by the Ministry of Commerce for fuel trading under Section 6 of the Fuel Oil Trading Act, B.E. 2521 (1978) and under Section 63 of the Fuel Oil Trading Act, B.E. 2543 (2000) which prescribed that, “The fuel trader as permitted by the Minister under Section 6 of the Fuel Oil Trading Act, B.E. 2521 (1978) is the fuel trader under Section 7 of this Act”; as a result, the Company which is a fuel trader under Section 7 of the said Act can also import fuel for domestic sale.

In 1986, the Company commenced to distribute fuels via the Company’s 32 petrol stations in the Southern Region. In the same year, the Company separated the fuel transportation business mentioned above from the fuel trading business by selling 6 fuel tankers and related assets to Siam Mongkol Marine Co., Ltd., its associated company. Subsequently, the Company expanded the number of its petrol stations almost throughout the regions.

On August 31, 1990, the Company became a listed company on The Stock Exchange of Thailand, having Baht 280 million paid-up capital, comprising 280 million common shares at the par value of Baht 10 each.

On February 8, 1993, the Company was converted to a public company limited, named “Siam United Services Public Co., Ltd.”

On November 26, 2010, the Extraordinary General Meeting No. 1/2553 resolved to change the name from “Siam United Services Public Co., Ltd.” to “SUSCO Public Co., Ltd.” and was certified by the Department of Business Development, Ministry of Commerce, to use the name “SUSCO Public Co., Ltd.” on December 15, 2010.

On November 16, 2012, the Extraordinary General Meeting No. 1/2555 passed a resolution approving the Company to acquire all shares in PETRONAS Retail (Thailand) Co., Ltd. and Universal Asset Co., Ltd. which traded fuels under “PETRONAS” trademark. The shares were acquired on December 3, 2012 and changed the names of the 5 PETRONAS companies to 1) SUSCO Dealers Co., Ltd., 2) SUSCO Retail Property Co., Ltd., 3) SUSCO Marketing Co., Ltd., 4) SUSCO Lubricants Co., Ltd., and 5) SUSCO Property Co., Ltd., and within 2014 would have to change the “PETRONAS” trademark to “SUSCO”.

On August 27, 2020, the Board of Directors’ Meeting No. 8/2563 approved the Share Repurchase Project for Financial Management purpose, in the maximum amount of Baht 180 million, being the number of shares to be repurchased not to exceed 55,000,000 shares or 5.00 percent of the total issued shares. At the end of the project, the Company repurchased a total of 50,000,100 shares or 4.55 percent of the total issued shares.

On September 30, 2020, The Company was recertified by Thailand's Private Sector Collective Action Coalition Against Corruption.

The Group of Companies has giving an importance to operate by taking into account the Environment, Social, and Governance. In 2021, the Board of Directors’ Meeting resolved to approve the sustainability policy framework and hired a consultant to collect carbon footprint data of the Company. In 2022, the Board of Directors set up the Corporate Governance and Sustainability Committee to oversee issues regarding the corporate governance for sustainability.

On September 29, 2022, the Board of Directors’ Meeting No. 9/2022 approved the reduction of repurchased capital totaling 50,005,500 shares or 4.55 % of current paid-up capital.

On October 27, 2022, the Board of Directors’ Meeting No. 10/2022 resolved to establish a new subsidiary, “SUSCO Beyond Co., Ltd.” to expand new potential business of which the registered capital is 100,000,000 Baht and 100 % of shares owned by the Company.

On February 28, 2023, The Extraordinary General Meeting of Shareholders No. 1/2023 resolved to sell 45,863,430 ordinary shares and 955,488 preferred shares of SUSCO Dealers Co, Ltd. to Sinopec (Hong Kong) Limited, resulting in a change in status from a subsidiary to a joint venture which later changed the name to “SINOPEC SUSCO Co., Ltd.”.

On April 26, 2023, the Board of Directors’ Meeting No. 5/2023 of SUSCO Beyond Co, Ltd. a subsidiary of the Company resolved to approved the joint investment in the battery exchange station and electric motorcycle rental project along with a maintenance center in Koh Samui, Surat Thani with AMR Asia Public Co, Ltd. by establishing an associate company under the name "AS MaCharge Co, Ltd." with an investment proportion of 40 % of the investment value.

On July 25, 2023, the Board of Directors’ Meeting No. 7/2023 resolved to approve the purchase of the newly issued ordinary shares and the ordinary shares of Siam Mongkol Marine Co, Ltd. from its shareholders and connected persons in an amount not exceeding 4,010,637 shares which made the Company holding shares in excess of 50 % of the registered capital of such associated company, thus Siam Mongkol Marine Co., Ltd. has changed its status to a subsidiary of the Company.

On September 30, 2023, the Company was recertified by Thailand’s Private Sector Collective Action Coalition Against Corruption.

As of December 31, 2023, the Company owned 3 oil depots, namely: Ratburana Oil Depot, Surat Thani Oil Depot, and Songkhla Oil Depot, and also had many joint oil depots to store fuels purchased by the Company from various sources for sale and legal reserve. The Company and its subsidiaries had a total of 262 petrol stations scattered almost throughout the country; 227 stations were operated by the Company and 35 stations were operated by dealers. In addition, SUSCO Beyond Co.Ltd., the subsidiary of the Company, owned 7 electric car showrooms and services, namely; Pratunam Phra-in branch, Ang Thong branch, Rama 2 branch, Rama 9 branch, Central Westgate branch, Central Pinklao branch and Vibhavadi 62 branch.