# Invoice Generator Create professional invoice totals instantly with tax, discounts, and line items included, making billing clients faster and more accurate. --- - **Canonical URL:** https://dothecalculation.com/calculators/invoice-generator - **Category:** Business tools - **Publisher:** Do The Calculation (https://dothecalculation.com) - **Cost:** Free, no account or sign-up required - **Privacy:** Runs entirely in the browser; inputs are never sent to a server - **Methodology:** https://dothecalculation.com/methodology --- ## Estimate invoice totals with discounts and tax Calculate invoice subtotals, apply percentage discounts, and add sales tax to get your final invoice grand total. - Net taxable total estimation - Discount savings calculation - Sales tax impact ## Tax and discount ordering When preparing invoices, discounts are standardly applied to the subtotal before sales tax is calculated. This is because tax is legally owed on the actual transactional price paid by the customer, not the pre-discount list price. This estimator follows standard invoicing conventions: Subtotal -> Subtract Discount -> Apply Tax Rate on Taxable Amount -> Add Tax to get Invoice Total. ## How to Use This Calculator Enter your invoice subtotal, any percentage discount you're offering, and the sales tax rate that applies to the sale. The calculator subtracts the discount from the subtotal to get the taxable amount, applies the tax rate to that discounted figure, then adds the tax back on to produce the final invoice total due. ## Worked Example: $2,500 Invoice A freelancer bills a $2,500 project subtotal, offers a 10% early-payment discount, and charges 8% sales tax. Discount amount: $2,500 × 10% = $250. Taxable amount: $2,500 − $250 = $2,250. Tax amount: $2,250 × 8% = $180. Invoice total: $2,250 + $180 = $2,430 — the final figure the client owes. ## Related Calculators If you're pricing hourly work before invoicing, start with the [freelance rate calculator](/calculators/freelance-rate-calculator), and track how long invoices sit unpaid with the [days sales outstanding calculator](/calculators/days-sales-outstanding-calculator). ## Frequently asked questions ### Are invoice discounts tax-deductible for the seller? Invoice discounts reduce your gross revenue, meaning you pay income tax on the actual discounted sales price. It is not listed as a separate expense deduction, but rather reduces taxable business revenue directly. ### Is tax calculated on the discounted amount? Yes, in almost all tax jurisdictions, sales tax (or VAT/GST) is calculated on the net taxable subtotal after any commercial discounts have been subtracted. ### What does "net 30" or "net 60" mean on an invoice? These terms specify the payment terms and due date. "Net 30" means the invoice is due and must be paid in full within 30 days of the invoice date. "Net 60" allows the client 60 days to complete the payment. ### Should I charge late fees on invoices, and how much? Yes, late fees encourage timely payments. A standard fee is 1.5% to 2% interest per month on the unpaid balance. Ensure these terms are clearly stated on your contract and invoice before billing. ### What details are required on a professional invoice? A professional invoice must include: unique invoice number, invoice date, business details (name, contact, tax ID), client details, description of services/goods, unit prices, subtotal, taxes, discounts, grand total, and payment instructions. ### How do I invoice clients in different currencies? Specify the billing currency clearly on the invoice. You can invoice in the client’s local currency or your own. It is best to clarify who covers bank exchange fees or specify a fixed exchange rate in your agreement. ### When should I charge VAT, Sales Tax, or GST? This depends on your business location and the client’s location. Standard rules require charging sales tax if you have physical or economic "nexus" in the client’s state. For digital cross-border B2B sales, taxes are often subject to reverse charge rules. ### What is the best way to handle deposit or retainer invoices? Send a deposit invoice for a percentage of the project cost before starting work. Once the project is complete, send a final invoice displaying the total project cost, deducting the deposit paid, and billing for the remaining balance. ### What is a PO number, and why do I need it on my invoice? A Purchase Order (PO) number is a document tracking number issued by the client’s finance department. Corporate clients require the PO number on the invoice to match and approve payments in their accounts payable systems. ### What is a proforma invoice? A proforma invoice is a preliminary bill sent to a buyer before shipment or service delivery. It outlines the estimated costs of goods and shipping but is not a request for payment and does not replace a commercial invoice. ### How do credit notes work? A credit note (or credit memo) is a document issued by a seller to reduce the amount owed on an invoice. It is used to correct errors, refund overpayments, or apply discounts after the original invoice has been issued. ### Should I pass credit card processing fees to the client? Many merchants charge a 2% to 3% surcharge to cover processing fees (like Stripe or credit cards). Check local regulations, as some jurisdictions limit or ban surcharging. Alternatively, build processing fees directly into your rates. ## Related concepts - **Taxable amount** — The portion of transaction value subject to sales tax, GST, or VAT. - **Invoice subtotal** — The sum of all line item prices before discounts, taxes, or shipping are applied. ## Related guides - [GST and Sales Tax: Calculation and Compliance Guide](https://dothecalculation.com/blog/business/gst-sales-tax-compliance) — Add or extract GST and sales tax, distinguish inclusive and exclusive pricing, and verify registration, taxability, location, invoices, returns, and records. - [Profit Margin: Formulas, Examples, and Calculator Guide](https://dothecalculation.com/blog/business/profit-margin-calculation) — Calculate gross, operating, and net profit margins, understand margin versus markup, and use each result to make better pricing and cost decisions. ## Related calculators - [Depreciation Calculator](https://dothecalculation.com/calculators/depreciation-calculator) — Estimate annual and accumulated depreciation of business assets using straight-line or declining balance methods for accurate accounting. - [GST Calculator](https://dothecalculation.com/calculators/gst-calculator) — Add or remove GST from any amount instantly using a custom tax rate to calculate accurate pre-tax and tax-inclusive prices for free. - [Cost of Goods Sold (COGS) Calculator](https://dothecalculation.com/calculators/cogs-calculator) — Calculate cost of goods sold using beginning and ending inventory plus direct costs for accurate accounting and profitability reporting. - [Economic Order Quantity (EOQ) Calculator](https://dothecalculation.com/calculators/eoq-calculator) — Find the optimal order quantity that minimizes total inventory holding costs and ordering costs for smarter, more efficient purchasing. - [Freelance Tax Deduction Calculator](https://dothecalculation.com/calculators/freelance-tax-deductions-calculator) — Estimate tax savings from eligible business expense write-offs to help freelancers and self-employed workers lower their taxable income. - [Invoice Factoring Cost Calculator](https://dothecalculation.com/calculators/invoice-factoring-cost-calculator) — Calculate the true cost, APR, and discount rate of factoring invoices to access immediate cash flow instead of waiting on client payments. --- _This calculator is for educational and business planning purposes only and does not constitute professional financial, tax, or legal advice. Verify all rates, margins, and contract terms before making operational business decisions._ --- _Source: [Do The Calculation](https://dothecalculation.com/calculators/invoice-generator). Quote freely with attribution and a link to this page._