An invoice is not just a request for money: it is an accounting and legal record. Leave something off and your client has a legitimate reason to delay, their accounts team has a reason to bounce it, and your bookkeeper has a problem at year end.
Requirements differ by country. The list below covers what is expected almost everywhere, but check the rules that apply where your business is registered — or ask your accountant.
About your business
- Your trading name, or your own name if you trade as a sole trader.
- Your business address.
- Your company or business registration number.
- Your VAT or tax registration number, if you are registered.
- The word “Invoice”, clearly, so it is not mistaken for a quote or a statement.
About your client
- Their business name, or their name if they are a private customer.
- Their billing address, and the site address if the work happened elsewhere.
- Their VAT number for cross-border business-to-business sales within the EU.
- A purchase order reference, if they use one. Large clients will not pay without it.
About the invoice itself
- The issue date, and the date the work was completed or the goods supplied.
- A unique invoice number from a continuous, gap-free sequence.
- A clear description of each item or service, with quantity and unit price.
- The tax rate applied to each line, and the tax amount.
- The total excluding tax, the total tax, and the total including tax.
- Any discount applied, shown as its own line.
Continuous numbering is where most people slip. Deleting an invoice to “start clean” leaves a gap in the sequence, and that gap is the first thing an auditor looks for. Cancel a wrong invoice with a credit note, never by deleting it.
About getting paid
- A specific due date, not a vague “30 days”. A date is harder to argue with.
- Your payment details: bank account, or a payment link.
- Your late payment terms, including any interest or fixed charge you will apply.
The details that get you paid faster
Beyond what is required, three habits shorten payment times noticeably. Describe the work in the client's own words rather than your internal shorthand, so whoever approves it recognises what they are approving. Send the invoice the day the job finishes, not at the end of the month. And address it to a named person, not to a generic inbox.