Effective tariff. (a) The effective tariff of a natural gas company is the tariff filed pursuant to the requirements of this part, and permitted by the Commission to be- come effective. A natural gas company must not directly or indirectly, xx- xxxx, charge, or collect any rate or charge for, or in connection with, the transportation or sale of natural gas subject to the jurisdiction of the Com- mission, or impose any classifications, practices, rules, or regulations, dif- ferent from those prescribed in its ef- fective tariff and executed service agreements on file with the Commis- sion, unless otherwise specifically per- mitted by order of the Commission.
