47 CFR 69.407 - Revenue accounting expenses in Account 6620.
(b) Revenue Accounting Expenses that are attributable to carrier's carrier access billing and collecting expense shall be apportioned among all carrier's carrier access elements except the Common Line element. Such expenses shall be apportioned in the same proportion as the combined investment in COE, C&WF and IOT apportioned to those elements.
(c) Revenue Accounting Expenses allocated to the interstate jurisdiction that are attributable to the provision of billing name and address information shall be assigned to the Billing Name and Address element.
(d) All other Revenue Accounting Expenses shall be assigned to the billing and collection category.