How to Decide Which Invoice Fields to Lock

Your client's accounts payable team needs a PO number on the invoice, but you don't have it yet. Their billing address changed last quarter and the one you have is stale. Meanwhile, you do not want anyone touching your bank details or the agreed price. Those three situations call for three different answers, and most invoicing tools give you one: a flat PDF where nothing can change without you redoing it.

The better way to think about an invoice is in three buckets. Some fields the recipient should be able to fix themselves. Some they should have to ask you about. Some should never move once you hit send. Set those up right and you stop the email loop before it starts.

The three kinds of fields on your invoice

Here is how JupiterInvoice splits them, and the reasoning holds whatever tool you use.

Recipient-editable. These are facts about the buyer that the buyer knows better than you do: the PO number, the billing entity, the billing address, and the AP contact. When the recipient opens the invoice link you share, they edit these directly. You get notified, and if something looks wrong you can revert it in a click. No new version is created for these; they are tracked as amendments to the current version.

Sender-only. These are the commercial terms you agreed to and own: line items, pricing, discounts, currency, payment terms, and the due date. The recipient cannot edit these. If they want a change, they leave a comment on the invoice and you decide. There is no formal approve or decline button, and no change-request queue. Someone asks, you look, you edit or you don't.

Locked. These never change once the invoice is issued: the invoice number, the issue date, your sender details, and your bank details. Locking them protects your books and protects the payment. An invoice number that shifts after sending is how bookkeeping breaks. Bank details that anyone could edit are a fraud risk.

Why letting the recipient edit billing fields saves you time

The slow death of a B2B invoice is almost always a billing detail. The AP team bounces it back because the legal entity is wrong, or there is no PO number, or it went to the wrong inbox. On a flat PDF, each of those means an email to you, a correction, a re-export, and a resend. Days gone.

Put the PO number, billing entity, address, and AP contact in the recipient's hands and they fix their own details on the spot. A client who needs to add a PO after you sent just types it in. The person who knows the correct billing entity enters it. You are notified and you can still revert anything that looks off, so you are not handing over control, just the typing.

This is the whole idea behind letting your customers edit their own invoice. It only works because the dangerous fields stay locked. Nobody can touch the amount or your bank account while fixing their own address.

Why price and terms stay in your hands

Line items, discounts, currency, payment terms, and the due date are the deal. If the recipient could edit those, the invoice stops being a record of what you agreed and becomes a draft anyone can rewrite. So they are sender-only.

The recipient still has a voice. If they think a line is wrong, or they want Net 45 instead of Net 30, they comment. You see the comment in context, right on the invoice, and you make the call. When you do change a commercial field, that creates a new version (V1, V2, and so on), so there is a clean trail of what the terms were and when they changed. The difference between a version and an amendment is covered in detail in versions vs amendments.

Keep in mind there is no formal workflow where a recipient approves an invoice for payment. There is no such button. The statuses are Draft, Sent, Viewed, and Paid, and that is it.

A sensible default setup for a small business

You do not have to configure much. The split above is the default, and for most small businesses billing other businesses it is the right one. The fields that follow the deal stay with you. The fields that follow the buyer go to the buyer. Payment and identity fields are frozen.

A few checks before you send:

• Confirm your bank details are correct, because they lock the moment you issue. Run an IBAN check first if you invoice internationally.
• Set your invoice number format once so it increments cleanly. The invoice numbering setup handles this.
• Fill the billing entity and address if you already know them. The recipient can correct them, but giving them a starting point is faster for everyone.
• Leave the PO number blank if you do not have it. The recipient adds it. A missing PO is a common reason invoices sit unpaid.
• Set payment terms and due date yourself, since those are the deal. The due date calculator works it out from your terms.

If you want the full setup aimed at your situation, invoicing built for small businesses walks through sending the first link and what the recipient sees.

What this looks like for the person paying you

The recipient opens the link with no account and no signup. They see your invoice, fix their own PO number and billing details, forward it to AP, and pay by card if you have connected Stripe, or report a payment they made another way. They cannot change your price or your bank details, and they cannot mark the invoice paid to dodge it. Once it is actually paid, their edits stop.

That is the point of locking some fields and opening others. The buyer handles what only they know, you keep control of the money and the terms, and the record stays clean. When you are ready, create an invoice and the three buckets are already set the way they should be.