A free modern professional invoice template you fill in online rather than download and wrestle with in a word processor. Indigo is the site's own default accent, so this is the same look you get when you open the generator with no style picked. It reads as neutral and corporate, which is why agencies bill with it: it does not compete with a client's own branding. It is free with no account and no watermark, the totals calculate themselves, and the PDF is generated on your own device.
Billing as an agency or studio
Agency invoices carry a risk a solo invoice does not: they are read by someone who did not commission the work. A marketing manager approves the project, then the invoice reaches a finance team who have never heard of you and are matching it against a purchase order. Everything on the document has to survive that handover.
Two practical consequences. Describe deliverables the way the contract or statement of work described them, not the way you refer to them internally. Phase 2 discovery means nothing to accounts payable; Brand identity design, as per SOW dated 3 June gets matched and paid. And put the purchase order or project reference in the notes if your client uses one, because an invoice without it usually joins a query queue rather than a payment run.
The neutral indigo accent is deliberate for the same reason. An agency invoice sits alongside invoices from a dozen other suppliers, and a document that shouts competes with the client's own branding for no benefit. Restraint reads as established.
This is one of 6 styles in the invoice templates gallery. None of them is a static file to download and edit: clicking through opens the real invoicegenerator with this style's accent and example data already applied, so what you see above is what you get. Replace the example business, client and line items with your own, and your draft saves automatically in this browser as you type.
Not sure what the document itself has to contain? How to write an invoice covers the fields every invoice needs, and invoice requirements by country covers what is legally required where you are.