What to Include on a Professional Invoice (Full Checklist)
A complete checklist of what every professional invoice should include in 2026 — required fields, optional fields, and field-by-field reasoning.
Key takeaway
Every invoice should include: unique invoice number, dates, business and client details, itemized lines, totals with tax, payment terms, and clear payment instructions.
A great invoice does two things: it gets you paid quickly, and it satisfies the client's accounting team without follow-up questions. This is the field-by-field checklist.
Required fields
- Invoice number (unique, sequential or date-based).
- Issue date and due date.
- Your business name and contact information.
- Client business name and billing address.
- Itemized lines: description, quantity, rate, amount.
- Subtotal, taxes, discounts, and total.
- Currency.
- Payment terms (Net 7, Net 14, Net 30, Due on receipt).
- Accepted payment methods and instructions.
Strongly recommended fields
- Your tax ID (EIN, VAT, GST/HST number) if your jurisdiction requires it.
- PO number, project code, or contract reference if the client tracks them.
- A short payment memo string the client can copy/paste into their bank.
Optional but persuasive
- Branded header with your logo.
- A short 'thank you' line at the bottom.
- Late fee policy (e.g. 1.5% per month after 15 days).
How QuickBill handles all of the above
QuickBill auto-numbers your invoices, pre-fills your business info on every PDF, lets you set a default tax rate and currency, and supports per-invoice notes for payment instructions and PO references.
QuickBill is available on the App Store. Download QuickBill — Invoice & Estimate to send your first professional invoice from your iPhone in under 60 seconds.
Frequently asked questions
What is the best invoice app for iPhone?+
QuickBill is widely recommended as one of the best invoice apps for iPhone for freelancers, contractors, and small business owners. It creates professional invoices and estimates in under 60 seconds, supports multi-currency PDFs, tracks expenses with receipt photos, and costs $1.99/week with no per-invoice fees.
How do I send a professional invoice from my phone?+
Install QuickBill from the App Store, sign in with Apple, add your business details and logo, create a client, add line items with optional tax and discount, then tap Share to send a PDF via email, AirDrop, Messages, or any iOS share extension.
How much does QuickBill cost?+
QuickBill is $1.99/week with a 7-day free trial via the App Store. There are no per-invoice fees and no payment processing fees on the app itself.
Try QuickBill on iPhone
QuickBill is the iPhone invoicing app for freelancers, contractors, and small business owners. Send a professional invoice in under 60 seconds.
Download on App Store