An invoice isn't admin. It's the moment your work turns into cash, or the moment it gets stuck for another month because you missed one detail.
Get these right and you remove the excuses not to pay you.
- Your business name, address, and VAT number if registered
- A unique invoice number and the date
- The client's details, and their purchase order number if they use one
- A clear description of what was delivered
- The amount, VAT, and the total
- Payment terms and your bank details
Two things quietly delay more invoices than anything else. A missing PO number, so the client's system rejects it. And a vague description, so someone has to go and check what it's for.
Not 'Consultancy £5,000'. Instead: 'Brand campaign, phase 2, per SOW dated 3 March, £5,000 plus VAT'.
And VAT: if you're registered, it's added on top and shown separately. It is never yours; you're collecting it for HMRC, so don't spend it.
Timing is a lever, not an afterthought.
Upfront or a deposit funds the start. 50/50 splits the risk. Milestone billing keeps cash arriving as the work does. Billing only on completion is the slowest and riskiest; you carry everything until the end.
Invoice promptly, invoice clearly, and bill as early as the work allows.