Effective dating

A sale's cost and rights depend on the day each thing happened. Prices change between PO and shipment, promotions carry date ranges that deductions cite months later, limits change mid-order, and Visa US interchange changes each April and October.

Sources: Bennett Jones, Cooley, RSM, Visa, Mayer Brown, Nacha on funds availability and Same Day ACH, Fiscal Service, Payments Canada on bill payments and RTR.

Store the price, promotion, terms, fee schedule and card product that applied to each order, invoice and payment at the time, not a pointer to today's version. Deduction fights turn on which version applied.

Ask an expert: how far back do retailers' post-audit deductions reach, and can you rebuild the price or promotion in force on the ship date?

A payment's cost, tax treatment and rights depend on the day it moved. Terms can start their clock at the invoice date, receipt of the invoice, receipt of goods or month end, depending on the contract. Bank details have an effective date too: many buyers hold payments to recently changed details. 1099 thresholds follow the payment date, not the invoice date.

Sources: IRS (12/2026) and IR-2026-03, Fiscal Service, Nacha on fraud monitoring and funds availability, FRB Services, USPS, Payments Canada; the card contract and Visa's settlement filing are listed in Sources.

Store the terms, tolerance, tax threshold and bank details that applied when each invoice was approved and each payment released, not a pointer to today's version.

Ask an expert: how do ERPs handle a supplier that crosses $2,000 in December 2026 after a mid-year bank change: whose TIN, and which threshold?

Every rate in an expense has an effective date, and the IRS mileage rate has two. It rose from 72.5¢ to 76¢ a mile on July 1, 2026, citing fuel prices, the first mid-year change since 2022. The 76¢ applies only if the miles were driven and the allowance paid on or after July 1: a June trip reimbursed in July stays at 72.5¢. The IRS per diem year starts October 1; through December, an employer on the high-low method keeps that method and uses old or new rates consistently for everyone.

Sources: Announcement 2026-11, Notice 2026-60, Rev. Proc. 2019-48, GSA, NJC, Nacha, Finance Canada, CFPB; Visa entries in Sources.

Key every rate to the expense date and the jurisdiction, and US mileage to the payment date too; store the rate you applied, not a pointer to today's table.

Ask an expert: when a rate changes mid-period, do customers re-rate claims that were submitted but not yet paid?

The price of a message depends on the day it was sent, and sometimes on which carrier memo you read.

Sources: AT&T change notice and carrier fee table (both secondary), Meta, FCC DA 26-12, Troutman Pepper Locke.

Meta runs a cleaner calendar: WhatsApp prices change only on January 1, April 1, July 1 or October 1, with at least a month's notice for a rate change and six for a model change. A template is charged at the category it holds when sent (Meta pricing).

The FCC splits dates in two. A rule can be "effective" while compliance waits for OMB (the White House office that approves paperwork burdens) and a Federal Register notice, as the SIM-swap and NG911 rules did. Track the compliance notice, not the vote.

Store two dates on every approval and every fee: when it took effect and when you learned about it. Finance and carriers will both ask what applied when a given message went out.

Ask an expert: when a carrier fee changes mid-month, do you re-rate messages already sent, and who decides which date applied?