You did the work, the client is happy, and now you need to get paid. A clear invoice, sent the same day, with a due date the client can't miss, does most of the job. This guide walks through what a freelance invoice needs, how to number it, which payment terms to pick and how to chase one that's late, then how to do all of it with Invoice Cat, our invoice app for iPhone.
What to put on a freelance invoice
- Your name or business name, and how to reach you.
- The client's name, and their address or company details if they ask for them.
- An invoice number that's never used twice.
- The issue date and the due date.
- What you did, one line per job or deliverable. For hourly work, the hours and your rate.
- The total, less any deposit already paid.
- How to pay you: bank details, IBAN, PayPal or whatever you use.
What an invoice has to show for tax, and whether you need a tax ID on it, depends on where you work and who you work for. Requirements differ from place to place, so check your local rules or ask an accountant. Invoice Cat does the sums; it doesn't give tax or legal advice.
Number your invoices
Give every invoice its own number, in order. It's how you and the client's accounts team talk about the same document, and it shows you at a glance if one went missing.
Invoice Cat does this for you. Your first invoice is INV-0001, and each new one is one past the highest number you've used. In Business, under Numbering, you can change the prefix and set where to start, and the row shows the next number. Coming from a spreadsheet or another app? Set Start at so your numbers carry on. You can also change the number on any one invoice under More options.
Pick payment terms
Payment terms say when the money is due. Agree them with the client before you start, and put them on every invoice.
In Invoice Cat, the Due row on each invoice offers On receipt, In 7 days, 14, 15, 30, 45 or 60 days, or Pick a date. New invoices start at 30 days; set your own default under Business, in Payment terms. The PDF shows the Due date and, for the day counts, the terms in plain words, such as "Due in 14 days".
Took a deposit up front? Open More options and type it under Deposit received. The invoice shows what was paid to date and the Balance due.
Make the invoice
- Set up your business once. Open Business and add your name, email, address and logo. Under How to pay you, write your bank, IBAN, PayPal, Zelle or Venmo details; they print on every invoice. Every field is optional, and there's no payment processor and no fees.
- Tap New invoice. Under Who's it for?, type the client's name. Each client you bill is saved, so next time tap Saved clients instead.
- Under What did you do?, add a line for each job. A description and an amount is enough. Billing hours? Tap × qty and type them: 1.5 is an hour and a half.
- Set the Due row. Tax, discounts, notes and Terms & conditions wait under More options.
Quoted the job first? Make an estimate, and when the client says yes, tap Turn into an invoice.
Send it, then mark it paid
Tap Preview & send to see the finished PDF. Then tap Send to open the share sheet, Print, or Email (shown when Mail is set up on your iPhone) to open Mail with the PDF attached and the client's email filled in, if you added one.
When the money arrives, tap Mark as paid. You'll find it on the preview and in the … menu on the invoice, or swipe right on it in the Invoices tab and tap Paid. If the payment came in earlier, change the date under More options, in Paid on. A paid invoice's PDF shows PAID and the date it was paid.
Follow up on an unpaid invoice
A late invoice has often just been forgotten. A calm, early reminder is a good first step:
- A day or two after the due date, send a short, friendly note with the invoice attached again.
- Say exactly what's owed: the invoice number, the amount and the original due date.
- Still nothing a week later? Ask whether anything is holding it up, and then call.
Invoice Cat doesn't send reminders by itself; you decide when to send one. It shows you who to chase. On Home, Overdue lists up to five invoices past their due date, oldest first, below what's outstanding in total. Open an overdue invoice and it says how many days overdue it is. In the Invoices tab, filter by Unpaid, Overdue or Paid, and the Clients tab shows what each client still owes.
To send the reminder, open the invoice and tap Preview & send, then Email or Send. The message that's filled in for you names the invoice number, the amount still owed and the due date; change the wording to suit before you send it.
Billing for hours?
If you bill by the hour, keep a timesheet as you go and invoice from it at the end of the week or month. See how to make a timesheet on iPhone and how to calculate hours worked. Doing your first invoice on the phone? How to make an invoice on iPhone covers tax, design and paper size.
What it costs
Invoices, estimates and clients are free and unlimited, and so are preview, send, email and print. There's no watermark, no ads, no account and no subscription. Invoice Cat Pro is an optional one-time purchase that adds Saved items (the services you bill often, added in a tap), Repeat monthly (a new copy of a regular invoice, ready each month when you open the app, for you to check and send) and Statements (one PDF with a client's invoices, what they paid and what they still owe). More on the Invoice Cat page.
Your invoices are kept on your device and in your own backups unless you share, save or print them.
Quick answers
What should a freelance invoice include?
Your details, the client's name, a unique invoice number, the issue and due dates, what you did with the amounts, the total still owed, and how to pay you.
How should I number my invoices?
In order, with no number used twice. Invoice Cat numbers them for you (INV-0001, INV-0002…), and you can set the prefix and where to start.
What do I do if a client doesn't pay?
Send a polite reminder with the invoice attached, the amount and the due date. Then follow up by phone. In Invoice Cat, Home lists overdue invoices so you know who to contact.
Try Invoice Cat
Try Invoice Cat: free, no watermark, no sign-up → iyio.com/apps/invoice-cat