It turns a short form into a tidy invoice and saves it as a PDF. You type who is selling, who is buying, and one line per product or service with its quantity, unit, unit price and, if it applies, a tax rate. The tool adds everything up, applies a discount to the whole invoice if you give one, works out the tax for each rate separately and shows the grand total, with a live preview of the page underneath. The PDF has real, selectable text (not a picture of text), so the buyer can search it and copy your bank details from it. Vietnamese, Spanish, Portuguese and Indonesian letters print correctly because the PDF embeds a font that has them.
Everything happens in your browser. The invoice, your client's address and your logo are never uploaded. If you want to come back to the same invoice later, you can ask the tool to remember it on this device; otherwise nothing is kept once you close the page.
How the totals are calculated
Every amount is calculated in whole cents (or whole dong, yen or won), with no floating-point arithmetic, so the lines always add up to the subtotal exactly. Each line is quantity times unit price, rounded half up to the currency's smallest unit. A discount on the whole invoice is spread over the lines in proportion to their amounts, so each tax rate is charged on its own discounted base; the spread pieces add up exactly to the discount. Tax is then rounded once per rate, not once per line, which is how most invoicing software and tax authorities expect it.
For example, 1 logo at 5,000,000 dong with 8% VAT and 12 months of hosting at 150,000 dong with 10% VAT give a subtotal of 6,800,000 dong, tax of 400,000 and 180,000, and a total of 7,380,000 dong. The VAT calculator is handy for checking a single price with or without tax, and the percentage calculator for a quick discount.
Is this a legal tax invoice?
That depends on where you are and who you are. In many countries a freelancer or small business may send an invoice made like this, as long as it carries the details the law requires (often: a sequential number, the date, both parties, a description, the amounts and the tax). In others, a tax invoice must be issued through an approved system. Vietnam is one of the latter: VAT invoices are electronic invoices issued through software connected to the tax authority, under Decree 123/2020/ND-CP as amended by Decree 70/2025/ND-CP (in force from 1 June 2025). A PDF from this tool is not one of those; in Vietnam use it as a quotation, a payment request or a commercial invoice for a foreign client, and issue the e-invoice through your provider. Rules change, so check the current rules for your country before relying on any invoice. Our article on invoice essentials and Vietnamese e-invoices explains what an invoice needs (as of October 2026).
