Rates stack by jurisdiction
State or national, county, city, and special-district rates can combine at the transaction’s sourced location, subject to product and seller rules.
Layered sales-tax invoice and reverse-tax analysis
Calculate the taxable base before applying the headline rate
Build a multi-line invoice with quantities, line and order discounts, partial exemptions, category surtaxes, state, county, city, and district layers, shipping rules, tax-exclusive or inclusive pricing, rounding comparison, rate sensitivity, and a complete tax worksheet.
Plan with context
The taxable base must be correct before any sales-tax rate is useful.
Product classification, discounts, exemptions, delivery, sourcing, jurisdiction layers, inclusive pricing, and rounding determine the amount to which a sales-tax percentage actually applies.
Not every line is fully taxable
Goods, services, food, medicine, digital products, and bundled transactions can be exempt, partially taxable, or subject to a separate category surtax.
Discount treatment affects the base
Line and order discounts usually reduce consideration before tax, but manufacturer rebates, coupons, trade-ins, and promotions may follow different local rules.
Shipping rules vary
Delivery, handling, installation, and freight can be taxable, exempt, or allocated between taxable and exempt goods depending on the jurisdiction and contract.
Inclusive pricing requires extraction
When displayed prices already contain tax, the tax portion must be divided out rather than calculated as the headline rate multiplied by the final amount.
Rounding can change an invoice
Rounding tax on every line can differ from calculating tax on the aggregate base and rounding once, especially with many low-price items.
Included
Five editable invoice lines, quantity, price, line and proportional order discounts, taxable percentage, item surtax, base exemption, four jurisdiction layers, shipping choice, exclusive or inclusive prices, line or invoice rounding, effective rate, nearby-rate sensitivity, Chart.js tax allocation, and line worksheet.
Not included
Live jurisdiction lookup, nexus determination, product taxability databases, tax holidays, origin-versus-destination sourcing, marketplace rules, resale certificates, coupon and rebate variants, returns, remittance filing, currency, VAT input credits, or legal tax advice.
Use it well
Confirm the sourced jurisdiction and product codes, document exemption certificates, match the platform’s rounding convention, and use current official rules or a sales-tax engine for actual billing and filing.