Make a proper invoice, as a PDF, in a couple of minutes

The first few invoices a business sends are usually made in a word processor, and they mostly work. What they lack is not design, it is the specific information that makes an invoice a document somebody can pay without asking you a question first, and each missing piece costs a few days.

For a UK business the required parts are unglamorous and worth getting right. The word invoice, a unique sequential number, your business name and address, the customer's name and address, a description of what was supplied, the date it was supplied and the date of the invoice, the amount, and the payment terms. If you are VAT registered there is more: your VAT number, the rate applied, and the tax broken out rather than folded into a total.

Sequential numbering is the requirement people improvise around and later regret. Numbers that restart per client, or that embed a date and then collide, make reconciliation harder for you and awkward at audit. One straight sequence is boring and does not go wrong.

Payment terms deserve more attention than they get, because vague terms cause more late payment than bad clients do. Payment due on receipt is not a date, and an invoice with no date is an invoice with no deadline. A specific due date, and a stated position on what happens after it, changes behaviour more than a polite chase does. Businesses in the UK have a statutory right to claim interest and a fixed sum in recovery costs on late commercial payments, and simply knowing that tends to firm up how the terms are written.

Everything is generated in your browser, which matters more here than for most applets. An invoice contains your client's name and address, what you did for them and what you charged, which is commercially sensitive on both sides. None of it is uploaded, because none of it needs to be.

This is a good applet for its own limits. It makes a document; it does not track whether the document was paid, chase it, or tell you what you are owed in total. When invoicing stops being a monthly document exercise and starts being a question about cash flow, the answer is a system rather than a form, which is roughly the point at which Terrarium exists.