D.C. Mun. Regs. r. 15-305
Payments shall be due within twenty (20) Days after the date the Bill is rendered. If the due date falls on a non-business Day, the due date shall be the next Business Day.
The date of payment shall be considered as the Day the payment is received at the offices of the Utility, Energy Supplier, Telecommunications Service Provider or an authorized agent. The Customer shall provide an accurate account number for prompt payment posting. Payments received without sufficient information to identify the Customer's account will be credited when the Utility is able to identify the account. Payments submitted electronically, by phone or computer, must be received within the Utility's established computer processing times for same day posting.
No late payment charge shall be levied on any amounts, including deferred payment installments, paid by the due date, or on amounts in dispute before the Commission. Utilities may levy a late payment charge on amounts that are not paid by the due date. Such late payment charges shall be established by tariffs in accordance with the procedure required by the Commission.
Customer payments shall be applied in the following order: first to the applicable Utility for arrears for Commission regulated Charges, oldest item first; next to arrears for non-regulated Charges (i.e., Energy Supplier Charges for gas supply or electricity); next to the Utility for current Commission-regulated Charges; finally, to current non-regulated Charges.
For Energy or Telecommunications services, subsections 305.1 through 305.4 shall not apply when the Utility, Energy Supplier or Telecommunications Service Provider and the Customer agree to different payment terms.
D.C. Mun. Regs. r. 15-305