📚 SafeKit Guides
Invoicing guides for real businesses
Plain-English guides to creating and sending invoices — what to include, how to number them, how tax works, and the difference between invoices, receipts and estimates. Every guide pairs with SafeKit’s free tools so you can put it into practice straight away.
How to create an invoiceA clear, step-by-step guide to creating a professional invoice: what to include, how to number it, how to work out tax and totals, and how to send it so you get paid on time.What to include on an invoiceA complete checklist of what a professional invoice should contain — the required essentials, the recommended extras, and the details that depend on your country and tax registration.Invoice vs receipt: what’s the difference?Invoices and receipts are easy to confuse but do opposite jobs. Learn the difference, when to send each, and what information each one should contain.Invoice vs estimate: when to use eachAn estimate proposes a price before work begins; an invoice requests payment after. Learn how they differ, how a quote becomes an invoice, and what each should include.How to number invoicesSequential, dated or client-based — learn simple, reliable ways to number your invoices, why consistency matters, and mistakes to avoid.How to calculate tax on an invoiceUnderstand tax-exclusive vs tax-inclusive pricing, how to apply a tax rate to an invoice, and how the subtotal, tax and total fit together — with a worked example.How to invoice as a freelancerA practical guide to invoicing as a freelancer or contractor: what to put on your invoice, how to set payment terms, how to bill for hourly and fixed work, and how to get paid on time.