When someone sends you an invoice through JupiterInvoice, you open it from the private link they shared. You can add or correct the purchase order number yourself, without an account and without waiting on the sender.
Step 1: Open the invoice link
Click the link the sender shared with you. The invoice opens in your browser.
Step 2: Find the PO number area
Look in the upper right of the invoice, near the currency details. If no PO is set yet, you will see a + Add PO number button. If one already exists, it shows under the PO Number label with an Edit link beneath it.
Step 3: Open the editor
Click + Add PO number or Edit. A text field appears where you can type the value, for example PO-2026-042.
Step 4: Save
Type the PO number and click Save (or press Enter). Click Cancel or press Escape to back out without changing anything.
Step 5: Confirmation
The page reloads showing the new PO number. The sender is emailed about the change, and the edit is saved as a new version so the change history is kept. Once an invoice is approved, paid, or voided it is locked, and the edit controls no longer appear.