TetraKits
Freelancers, small shops, and finance teams send invoices every week — but desktop software and paid SaaS tools add friction when you only need a clean PDF today. An online invoice generator lets you fill in company and client details, add products, show tax and discounts, and export a print-ready file without installing anything or creating an account.
This guide walks through what belongs on a professional invoice, how to use the free TetraKits Invoice Generator with inline edit buttons on every field, and how to download a PDF that stays on your device from start to finish.
Why create invoices online
Browser-based invoicing fits modern workflows:
- No install — works on Mac, Windows, Chromebooks, and phones.
- Instant PDF — email or print right after you finish editing.
- Low cost — TetraKits is free with no per-invoice fees.
- Privacy — your client list and amounts are not uploaded to our servers.
- Flexible branding — upload your logo and signature image on the preview.
For recurring billing you may eventually connect accounting software; for one-off projects, deposits, and contractor payments, a fast generator is often enough.
What to include on an invoice
Most business invoices share the same building blocks. Include enough detail that accounts payable can approve payment without back-and-forth email.
Header and reference
- Your company name, address, phone, and email
- Invoice title (often “INVOICE”)
- Unique reference or invoice number (e.g. INV-000042)
- Invoice date and payment due date
Client (“bill to”) block
- Client or company name
- Billing address and contact details
Line items
Each row should describe what you delivered: product or service name, optional description, quantity, unit price, discounts, and tax if applicable. A clear amount column helps clients reconcile totals.
Totals and message
- Subtotal, total discount, tax, and grand total
- Payment terms or thank-you message in the notes area
- Signature block with name and department
Inline editing with pencil buttons
TetraKits uses a what-you-see-is-what-you-get layout: the preview is the document. Yellow pencil buttons beside each label and value focus the field for editing; you can also click text directly because fields are content-editable.
- Open the Invoice Generator.
- Click a pencil icon next to company name, client details, dates, or the invoice title.
- Type your real business information — placeholders update in place.
- Upload a logo or signature with the cloud upload areas when ready.
This pattern matches professional invoice UIs where every string is customizable without opening a separate settings panel.
Line items, tax, and discount
Use + Add line item for each product or service. Enter quantity and price; the amount column recalculates automatically. In the sidebar:
- Show discount column — enter a percentage per line.
- Show tax — pick a tax rate (0%, 5%, 10%, 11%, etc.).
- Show unit column — optional unit labels such as pcs, hours, or licenses.
- Currency — tap the currency button to switch codes (USD, EUR, IDR, and more).
Summary rows on the right show subtotal, total discount in parentheses, tax, and the bold total — all formatted for your selected currency.
Download invoice as PDF
When the preview looks correct, click Download Invoice PDF. The tool captures the preview with html2canvas and builds an A4 PDF with jsPDF. Multi-page support splits tall invoices across pages. The filename uses your reference number so files sort cleanly in downloads folders.
Before sending:
- Proofread client name and amounts.
- Confirm due date and payment instructions in the message area.
- Re-download if you change line items after the first export.
Need to edit an existing PDF instead? Use the TetraKits PDF Editor for text changes on uploaded documents.
Privacy and security
Invoice data is processed locally in your browser. TetraKits does not store your company details, client list, or line items on a server for this tool. That makes it suitable for sensitive amounts and unreleased project names — though you should still follow your own backup and record-keeping policies for tax compliance.
Frequently asked questions
Is the TetraKits invoice generator really free?
Yes. There is no signup, subscription, or per-download fee.
Can I add my logo and signature?
Yes. Use Upload logo and Upload signature on the preview. Images stay in your browser session until you refresh.
Does it work on mobile?
Yes. The layout stacks on small screens so you can edit fields and download PDF from a phone.
Which currencies are supported?
Common codes are built in; you can enter any valid ISO currency code via the currency button for localized formatting.
