Invoicing guides
Plain-English answers to the questions businesses actually ask about invoicing, payment terms and getting paid.
How to invoice a customer in another currency
Invoice in the currency you agreed, state it explicitly on every amount, and settle through a gateway that supports it. If your tax authority requires it, also restate the tax amount in your local currency at a published rate.
How to refund a paid invoice, in full or in part
Refunding a paid invoice takes two steps: issue a credit note for the amount no longer owed, then return the money to the original payment method. Never delete the invoice — the credit note is the record.
How to take card payments on an invoice
To accept card payments on an invoice you need a payment gateway and a merchant account. The invoice carries a pay link, the customer pays with a card, and the funds settle into your account under your own acquiring agreement.
How to write an invoice
An invoice needs six things to be payable: who you are, who owes you, a unique number, an issue date, what you supplied with the amounts, and how and when to pay. Everything else is optional.
Invoice numbering — formats, sequences, and why gaps matter
Invoice numbers must be unique and sequential with no gaps. Use a simple incrementing sequence, optionally prefixed by year or series, and never reuse or renumber — a gap reads to an auditor as a hidden invoice.
Invoice payment terms explained — Net 30, due on receipt, and the rest
Payment terms say when an invoice is due. Net 30 means 30 days from the invoice date, due on receipt means immediately, and 2/10 Net 30 offers a discount for paying early. Always also state the actual date.
What is a credit note, and when do you issue one?
A credit note cancels or reduces an invoice you have already issued. Issue one to correct an overcharge, cancel undelivered work, or refund a paid invoice — never by editing the original.
What must an invoice legally include?
A compliant invoice needs your identity and registration details, the customer's details, a unique sequential number, the issue and supply dates, an itemised description with amounts, and the tax charged per rate.