The EC's meeting on Tuesday endorsed the senators-elect in the outstanding 15 of the 77 provinces, said secretary general Puchong Nutrawong.
They are Khunying Jaruvan Maintaka (Bangkok), Buntoon Kiatkongchichai (Chaiyaphum), Marut Rojanapiyawong (Nakhon Nayok), Pipatchai Pakratchatanon (Phetchabun), Pol Sen Sgt Maj Bulan Ratkampan (Phrae), Surapol Santichotinan (Mae Hong Son), Sakda Sriviriyapaibul (Ranong), Pratuan Sutthi-amnuaydej (Lop Buri), Varavud Norkham (Lampang), Tri Danpaibul (Lamphun), Villada Inchat (Si Sa Ket), ACM Sujin Chamchoi (Surat Thani), Prapas Nuansamli (Nong Bua Lam Phu), Yaninart Khemnak (Amnat Charoen) and Somchai Laosaicheua (Ubon Ratchathani).
The EC has not finished considering the complaints against the endorsement of these 15 senators, but has to meet today's deadline for preliminary consideration, set at 30 days after the election date.
The EC still has one year to consider the complaints and to remove the senators if they were found to have broken the election law.
Mr Puchong said the EC should be able to complete the consideration process in three months.