TOT Corp has reissued an ultimatum to True Move and DTAC to pay it a total of nearly USD100 million in backdated network access charges, or else it will block three million new mobile phone numbers belonging to the cellcos from connecting to its fixed line network. Continued refusal to pay could prompt the state-owned telco to block access to its network for all 25 million mobile numbers, around 18 million of them active, held by the two companies, said Supa Piyajitti, a TOT director and deputy permanent secretary to the Finance Ministry. She added that because DTAC and True Move operated under concessions from TOT’s sister organisation, international services provider CAT Telecom, CAT would be held responsible for paying access charges on behalf of the two private operators; if CAT could not pay the charges, then it would be obliged to ask TOT to block their numbers. TOT president Somkual Bruminhent said DTAC and True Move had stopped paying access charges in November and now owed THB3.54 billion (USD97 million). DTAC and True Move argue that new interconnection rate agreements should take precedence over access charges paid to state telecom agencies. DTAC is petitioning the Administrative Court to seek a resolution with TOT.