Free Invoice Software for Small Business — Send E-Invoices Online

Create branded invoices online and send them electronically — emailed from the app or downloaded as a pixel-perfect PDF. Automatic invoice numbering, 100+ currencies, GST and VAT fields, and quotes, POs, and delivery notes linked in one free account.

What Is E-Invoice Sending Software?

E-invoice sending software delivers an invoice to your client electronically — as an email sent straight from the app, a PDF you download and attach, or a secure link the client opens in any browser — and then tracks what happens next: sent, paid, or overdue. No printer, no stamps, no "did you get my invoice?" calls. ProeInvoice is online invoice software that creates, numbers, sends, and tracks invoices for small businesses and freelancers, entirely in the browser.

Delivery is only half of e-invoicing; confirmation is the other half. Better tools pair sending with read receipts or viewed alerts, because an invoice that has been opened is an invoice you can politely chase. ProeInvoice keeps that confirmation explicit: every invoice carries a status — draft, sent, paid, partially paid, overdue, or cancelled — so your dashboard shows exactly where each dollar stands without inbox digging. Some platforms also push invoices over SMS, WhatsApp, or iMessage; for US business clients, an emailed PDF with a clear subject line remains the standard, and it keeps your formatting intact on every device.

The free tier works in two layers. The guest invoice generator creates and downloads unlimited invoices with no sign-up, no watermark, and no invoice cap — handy when you bill occasionally. A free account adds the software layer: saved clients and items, invoice history, email sending, payment tracking, and dashboard analytics. No credit card and no trial clock — nothing that keeps online invoicing software free for a month and then bills $19–$40 monthly. And here's the part most "free" tools soft-pedal: they monetize card processing at 2.9% + $0.30 to 3.49% + $0.49 per transaction, so $10,000 of client card payments costs roughly $290–$349 a month on a "free" plan. ProeInvoice doesn't process payments at all. You state your own bank details, ACH transfer instructions, or preferred payment methods on the invoice — and keep 100% of what clients pay.

International billing is built in. Choose from 100+ currencies — USD, EUR, GBP, CAD, AUD, INR, AED — and subtotals, tax lines, and amounts due format themselves correctly for each one. The tax field is label-agnostic: name it sales tax, VAT, or GST, set the rate per invoice, and ProeInvoice calculates the tax and grand total automatically while your tax ID prints from your business profile. That matters when you invoice a UK client under VAT on Monday and a Texas client at 8.25% sales tax on Tuesday.

The genuine difference from single-purpose tools: your invoices live next to quotations, purchase orders, and delivery notes on one platform — free quote and invoice software for small business under a single login. Convert an accepted quotation into an invoice in one click, reference the client's PO number on the invoice that fulfils it, and link a delivery note to the shipment it documents. One business profile and one client library feed all four document types. And to be precise about a term that means two things: in several countries, "e-invoicing" also refers to government-mandated structured formats and clearance networks — our e-invoicing compliance guide (linked below) covers Peppol and country mandates separately.

What This E-Invoicing Software Includes

Electronic invoice delivery

Send invoices by email from the app or export a print-ready PDF to attach yourself. Status moves from draft to sent to paid so nothing slips through.

Built-in invoice number generator

Every invoice takes the next sequential number automatically — set a prefix like INV once and numbering runs gap-free, with no duplicates, ever.

100+ currencies

Bill in USD, EUR, GBP, INR, AED, and more. Currency symbols, subtotals, and totals format correctly for each client automatically.

GST, VAT & sales tax fields

Rename the tax label to match your regime, set any rate, and show your tax ID. Tax lines and grand totals calculate themselves.

Linked quotes, POs & delivery notes

Convert accepted quotations to invoices, reference purchase order numbers, and tie delivery notes to shipments — four document types, one client library.

Free core, no processing cut

Unlimited invoices and unlimited clients, free. ProeInvoice takes no percentage of your payments because it never touches them.

How to Send an E-Invoice in 3 Steps

1. Create the invoice

Pick a saved client or add a new one, list line items with quantities and unit prices, choose the currency, and apply your tax rate.

2. Brand and number it

Your logo, accent color, and payment terms apply automatically, and the invoice number generator assigns the next number in your sequence.

3. Send and track

Email it from the app or download the PDF and attach it yourself. Mark it sent, watch for paid or overdue, and follow up using the number as reference.

Invoice Numbers, Sending Habits, and Getting Paid

A quick word on numbering, because auditors and accountants care about it more than most owners expect. An invoice number is the unique identifier that lets you and the client reference one specific transaction, and sequential, gap-free numbering is the accounting best practice — missing numbers are how you detect lost or fraudulent invoices. No US federal law or state financial regulation prescribes a format, so pick one and stay consistent: a plain sequence padded with zeros (0001, 0002), a company-abbreviation prefix (INV-0042), a date-based pattern (2026-07-014), or a customer-code format (ACME-0007) if you organize by client. ProeInvoice's invoice number generator handles this automatically: set the prefix and starting number once, and every new invoice takes the next number. Never reuse a number, even on a cancelled invoice — if INV-0042 is voided, the next invoice is still INV-0043.

Sending habits move payment dates more than invoice design does. Send the invoice the day the work completes; quick invoicing measurably speeds up payment. Write a subject line the client's bookkeeper can file blind — "Invoice INV-0042 — July site maintenance" — and keep the email body to four things: amount due, due date, accepted payment methods, and the PDF attached. The itemized breakdown with descriptions, quantities, unit prices, and taxes belongs on the invoice itself. This is where digital invoice software earns its keep: the PDF renders identically on a phone, a laptop, and the client's printout.

When an invoice goes overdue, escalate in order. First verify your own accuracy — a wrong PO number or total causes more silence than bad faith does. Then send a courtesy reminder on the due date referencing the invoice number, then a firmer note stating the outstanding amount and days overdue, and finally a notice invoking whatever late-fee policy your payment terms stated. Partial payments get their own status in ProeInvoice — partially paid — so a half-settled invoice never masquerades as a closed one.

Two honest notes. First, ProeInvoice concentrates on creating, sending, and tracking business documents. If your operation needs recurring invoices on a schedule, billable-hours time tracking, timesheets, expense capture, or a customer portal, a paid accounting suite serves those needs better. Second, whichever tool you use, a complete invoice carries the same fields: invoice number and date, both parties' contact information, the client's PO number where one exists, itemized descriptions with quantities and unit prices, subtotal, tax, grand total, payment terms such as Net 30 or due on receipt, and the payment options you accept.

This page is informational, not tax or legal advice. For US recordkeeping requirements around invoices and supporting documents, the IRS's small-business records guidance is the primary source (last verified July 2026).