If you need a line item, price, due date, or anything else changed, or you just have a question, use the two-way Comments thread on the shared invoice page. The sender gets an email for every comment you post and can reply in the same thread. You can edit your own PO and billing details directly, but other changes go through the sender, and this is how you ask.
Step 1: Open the invoice link
Click the link the sender shared. The invoice opens in your browser.
Step 2: Open the Comments panel
Scroll to the bottom and click Comments to expand the thread. Any earlier messages between you and the sender appear here.
Step 3: Add your details
Enter Your email (required so the sender can reply) and optionally your name.
Step 4: Write your message
In the comment box, describe your question or the change you are requesting, for example a wrong quantity or a different due date. Be specific so the sender can act on it.
Step 5: Post it
Click Post comment. The sender gets an email that you posted and can respond in the thread or update the invoice.