Online invoicing: the complete guide
What goes on a proper invoice, how to set payment terms that get you paid, how to accept card payments online, and how to chase late invoices without the awkwardness.
In short
A complete invoice names a unique number, both parties, an issue and due date, itemised lines, and the total with any tax — plus a way to pay. The fastest way to get paid is short, specific terms, sending the moment the work is done, and offering one-click online card payment.
An invoice is not just a bill — it is the moment your work turns into money. A clear, professional, easy-to-pay invoice gets paid faster and saves you the dreaded follow-up. This guide covers everything from the fields you must include to the small choices that quietly shave days off how long you wait to get paid.
What every invoice must include
A complete invoice removes any excuse to delay payment. Missing details — a number, a due date, a way to pay — are the most common reason an invoice sits in someone’s inbox.
- A unique invoice number for your records and theirs
- Your business name and contact details, and the client’s
- Issue date and a clear due date (not just "on receipt")
- Itemised lines with quantity, rate and line total
- Subtotal, any tax, and a bold grand total
- How to pay — a card link, bank details, or both
Payment terms that actually get you paid
"Net 30" is a habit, not a law. Shorter, specific terms get paid sooner because they remove ambiguity. State the term on the invoice and, ideally, agree it before you start the work.
| Term | Means | Best for |
|---|---|---|
| Due on receipt | Pay now | Small jobs, new clients |
| Net 7 / Net 14 | Pay within 7 / 14 days | Most freelance work |
| Net 30 | Pay within 30 days | Larger or corporate clients |
| Deposit + balance | Pay part up front | Big projects, new relationships |
Accept payment online
The single biggest lever on getting paid faster is letting people pay the instant they open the invoice. Connect Stripe to CoreInvoice and every invoice carries a "Pay now" button — money lands straight in your account, and the invoice marks itself paid.
- Card payment removes the "I’ll do a transfer later" delay
- The invoice updates to Paid automatically — no manual reconciling
- You still keep bank transfer as an option for clients who prefer it
Send it so it gets seen
Send from a name your client recognises, with a subject line that says exactly what it is and when it is due. A short, warm note beats a bare attachment. Keep a copy of what you sent and when — CoreInvoice timestamps it for you.
Chasing late invoices without the awkwardness
Most late payments are forgetfulness, not malice. A calm, scheduled reminder cadence collects the vast majority without ever needing a hard conversation.
- A friendly nudge the day after the due date
- A firmer reminder at one week overdue, restating how to pay
- A short personal message at two weeks
- Keep every reminder polite — you want the next job too
Recurring and repeat work
For retainers and subscriptions, duplicate a previous invoice or set one to repeat so you are not rebuilding the same line items every month. Consistency here is what turns sporadic income into predictable cash flow.
FAQ
Do I need to charge tax on an invoice?+
It depends on where you and your client are and whether you are registered for sales tax or VAT. CoreInvoice lets you add a tax line per invoice; check your local rules for the rate and whether to apply it.
How do I get paid faster?+
Use short, specific payment terms, send the invoice the moment the work is done, and enable online card payment so clients can pay in one click.
Can clients pay an invoice by card?+
Yes. Connect Stripe and every CoreInvoice gets a secure "Pay now" button; the invoice marks itself paid automatically once the payment clears.
Send a professional invoice
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