Alaska, Delaware, Montana, New Hampshire, and Oregon have no statewide sales tax. However, some Alaska localities charge local sales tax. If you're in these states and paid sales tax on an out-of-state or online purchase, use reverse calculation with that rate. For Alaska local tax jurisdictions, use the specific local rate. In other no-tax states, you typically won't need reverse calculations unless dealing with out-of-state purchases subject to use tax.

Proper reverse tax calculations ensure compliance by maintaining accurate records of tax collected, properly separating revenue from tax liability, enabling correct tax return filing, supporting audit defense, and demonstrating systematic business practices to tax authorities. Compliance requires showing that tax was correctly calculated on appropriate base amounts. Reverse calculations provide this documentation and verification mechanism.

Online purchases typically use destination-based tax rates (where you receive the item). Check your order confirmation or invoice for the total amount paid and the tax rate charged. Enter these into the reverse calculator to determine the pre-tax price. This is useful for expense tracking, budgeting, or when you need to report pre-tax purchase amounts. Remember that marketplace facilitators like Amazon often collect and show tax separately on invoices.