Client self-fill

Self-fill is a feature that lets your client provide their own purchaser details on an invoice. This is useful when you don't have the client's full billing information -- their legal business name, mailing address, or business number.

Instead of asking your client for these details over email or chat, you can send them a link and they fill in a simple form directly on the invoice.

Each invoice has a special purchaser link (e.g. biller.ca/i/abc123token) that opens a form for the purchaser details. Here's the flow:

1. You create an invoice from an income entry as usual
2. You share the purchaser link with your client (via email, text, or chat)
3. Your client opens the link and sees a form with fields for their name, address, and business number
4. Your client submits the form -- no Biller account or sign-in is needed
5. The invoice is updated with the client's details, and you receive a notification

To get the self-fill link, open the invoice and click "Purchaser Link". The link is copied to your clipboard, ready to paste into a message.

The self-fill link is different from the public invoice link. The public link (inv/...) shows the invoice in read-only mode. The purchaser link (i/...) shows an editable form for the client's details only.

Each purchaser link contains a unique token, so only someone with the link can access the form.