Freelance work is usually sold in days and hours, but most invoice templates are built for selling widgets — quantity, unit price, done. So freelancers end up bending the columns: is a "unit" a day? An hour? The project? Your client's finance team should not have to decode it. InvoiceIt's freelance invoice generator uses days and day rates as the native format: five days at £350 reads as exactly that, on screen and on the PDF.
The single most useful line on a freelance invoice is a clear payment term: when payment is due and how to pay. "Payment within 14 days" or "within 30 days" with your account details beneath it removes every innocent excuse for delay. It is also worth knowing that UK law is on your side: under the Late Payment of Commercial Debts legislation, businesses that pay late owe statutory interest and a fixed compensation fee — you rarely need to invoke it, but knowing it exists changes the tone of a chasing email.
A clean, consistently numbered invoice does quiet work for your reputation. The generator handles sequential numbering, dates and totals automatically, remembers your details on your device for next time, and produces a PDF that looks like it came from a business that has done this a hundred times — even if it is your first.