Plenty of practices never connect anything else, and invoicing works fine that way. A patient hands you cash, you write down that they did, and the paperwork exists without a second system.
Off, Manual or Automatic
Invoicing is off until you turn it on under Settings → Billing → Invoicing, and while it's off nothing about it appears anywhere: no Billing tab on a patient, no Invoices item in the sidebar. Manual means you create and issue each invoice yourself. Automatic does the same and also prepares a draft whenever you mark a chart complete. It is your call per practice, and you can switch at any time.
Your invoice, payment and receipt history stays put if you turn it off again, and it exports with the rest of your data as its own CSV files.
Price a service once
Each service can carry a price, set next to its duration under Settings → Scheduling. Choosing the service on an invoice line fills in the description and amount, and you can still change either on the invoice itself or type a line from scratch. A line has a quantity, so three of the same herbal formula is one line.
Raising a price later never changes an invoice you've already issued. A January rate change can't restate what you sent in December.
A draft first, then Issue
Open a patient's Billing tab and choose Invoice. Saving gives you a draft with no invoice number yet, which you can edit or delete and which a patient never sees. When it's right, choose Issue. That assigns the next number, records your practice details as they are today, and makes the invoice final.
Payment terms (due on receipt, or net 7 through net 60) count from the day you issue, not the day you drafted. Standing text, such as payment instructions or a cancellation policy, prints at the bottom of every invoice, and your logo and accent color go on every one. Both live under Settings → Billing, as do the invoice and receipt prefixes and the next number, so numbering can carry on from your old system. See Your logo and colors and Invoice and receipt numbers.
Record how the patient paid
An issued invoice with a balance has a Record payment button. The amount is pre-filled with what's still owed, and you can lower it for a partial payment. Pick how they actually paid: cash, check, Venmo, Zelle, bank transfer or other. You never set the status yourself. A partly covered invoice becomes Partially paid, and a fully covered one becomes Paid.
Choose PDF on any issued invoice to download it and print it or hand it over. Goji doesn't email invoices yet. Each payment also gets its own numbered receipt, which is covered in Receipts.
If you later connect your own Square account, the same button becomes a Collect payment menu with card, reader and saved-card options. See Charging a card. Connecting it is optional.
When something's wrong
An issued invoice can't be edited, because someone may already have paid it or handed it to an accountant. Void it and issue a replacement, or add a line that adjusts the amount. Voiding asks for a reason, saves it with the invoice, and prints it on the PDF under a large VOID mark. A voided invoice keeps its number, and only drafts can be deleted.
Across the practice, and for the patient
Invoices in the sidebar is the practice-wide view, with tabs for drafts, outstanding invoices, paid ones, packages and activity. That's where you answer the month-end question a single patient's record can't. Seeing the whole practice covers it.
A patient with portal access sees their own issued invoices and receipts to download, what they owe or hold in credit, and any prepaid sessions left. Drafts stay yours. See What patients see.
Is it an invoice, a receipt or a superbill? An invoice says what the patient owes, a receipt says they paid, and a superbill carries the diagnosis and procedure codes for their own insurance claim. One visit can produce all three.