The Bt9.1 million sum was donated by OAI Leasing Co Ltd, a company owned by former prime minister Thaksin Shinawatra's daughter Pinthongta.
Individuals and companies must declare their names when donating over Bt1,000 to a political party. They are barred from donating over Bt10 million to a political party in a year.
The commission's data showed that in the month, members of Democrat Party donated Bt1.465 million to the party.
Donation to the Forest Land Reclamation Party amounted to Bt1 million; Cooperative Power Party Bt444,500; Bhum Jai Thai Party Bt300,000; Matubhum Party Bt120,000; Dumrongthai Party Bt95,000; Chart Pattana Party Bt40,000; Social Action Party Bt5,000 and Civil Peace Party Bt5,000.