You have Invoice Ninja on your server, and you have an agent in the chat that can read its files, query its database, and restart its services. Most days you do not need the admin UI at all — the jobs below are things you can simply say. Here are ten everyday tasks, each with a phrase you can type as-is.

1. Mark a stack of invoices paid from your bank statement

Bank transfers arrive with no invoice number attached. The agent can match amounts and client names against your open invoices and record each payment inside the app, so client balances, statements, and reports all stay correct. It will flag anything ambiguous instead of guessing. Try: “Here are the transfers from yesterday — match them to open invoices and mark them paid, and ask me about anything that does not fit.”

Recording the payment through the app matters more than it looks. If you just note it in a spreadsheet, the invoice status, the client statement, and your profit and loss report will quietly disagree with each other. The agent works through the app’s own logic, so partial payments and overpayments are handled the way the reports expect.

2. Turn an approved quote into a sent invoice

Quotes in Invoice Ninja convert to invoices with the line items carried over, so retyping is never needed. Ask the agent to convert a specific quote, set the payment terms, and email it to the client’s contact from inside the app. Try: “Quote 0042 for Acme was approved — convert it to an invoice, set Net 14 terms, and send it to their accounts contact.”

3. Log a month of receipts as expenses

Expense capture is where every freelancer falls behind. Drop scanned receipts into a folder and the agent can read the vendor, date, and amount on each one, create the expense entries with sensible categories, and attach the scan to each record so your bookkeeping has proof. Try: “Everything in /uploads/receipts/january is a business expense — create them, guess the category, attach each scan, and show me the ones you are unsure about.”

It can also create any missing vendors and categories first, so the import does not leave a mess of one-off names. If a receipt is unreadable or the numbers do not add up, it says so instead of inventing a figure.

4. Set up a new client completely

A proper client record is more than a name: contacts, currency, payment terms, and default notes all matter when the first invoice goes out. The agent can fill all of it in one pass and show you a summary before it saves anything. Try: “Add a client called Harbor Dental Ltd, contact Dr. Chen, currency EUR, payment terms Net 30, default payment method bank transfer.”

5. Fix a broken invoice number

Duplicate or jumped invoice numbers usually happen after an import or a manual edit. The agent can check the generated-number settings, find where the counter went wrong, and correct it — renaming only safe drafts, and telling you honestly if a sent invoice should be left alone. Try: “Invoice 2026-014 came out twice — check the counter, fix the draft one, and make sure the next number is right.”

Generated numbers live in the settings as a plain-text pattern: a prefix, the year, and a counter. Once the agent shows you the pattern, you can change the scheme itself — pad counters to four digits, or start quotes at a different number than invoices.

6. Resend an invoice that never arrived

When a client says they never got an invoice, the first question is whether the app actually sent it. The agent can check the email log, spot a typo in the contact address, fix it, and resend — or copy the payment link and send that instead. Try: “Atlas Ventures says they never got invoice 0031 — check whether it went out, fix the address if it is wrong, and resend with the payment link.”

7. Issue a credit note and apply it

Overbilling, a cancelled part of a job, a goodwill discount after the fact — all of these are credits in Invoice Ninja. The agent can create the credit, apply it against the open invoice or leave it on the client’s account, and include a short explanation line so the paperwork reads clean. Try: “We agreed to drop the rush fee on invoice 0033 — issue a credit for that amount, apply it to the invoice, and tell me their new balance.”

8. Update prices across your product library

Rates change. Updating them one by one in the product list is tedious and error-prone. The agent can update your product records in bulk, show a before-and-after list, and leave already-issued invoices untouched. Try: “My day rate goes from 80 to 90 dollars next month — update the product library but do not touch issued invoices.”

9. Pull numbers for your accountant

End of quarter, your accountant wants the books. The agent can run the invoice and expense reports for the period, export them as CSV, generate the profit and loss report as PDF, and drop everything in one folder. Try: “Give me last quarter’s invoices and expenses as CSV plus the P&L as PDF, zipped in a folder called Q3-books.”

It can also produce a client statement for anyone your accountant asks about. If the layout is not what they want, describe the change once — the agent saves the export script and it runs identically every quarter.

10. Undo a mistake without breaking history

Payments get applied to the wrong invoice, duplicates get created, a job gets billed to the wrong client. The agent can move a payment between invoices, delete a stray draft, and walk you through what is safe to change on a sent invoice. It will tell you what it changed and why. Try: “The 1,200 dollar payment from Bluefin got booked to invoice 0019 instead of 0021 — move it and show me their balance after.”

The rule it applies: drafts are safe to edit or delete, sent invoices are corrected with credits rather than rewrites. Ask it to explain the difference once and you will handle the next mistake yourself.

See it in action

Official walkthroughs from the Invoice Ninja team:

Worth a watch next:

• Grouped Report, Dashboard Widgets + Quickbooks Sync! — the dashboard and reporting features behind several of the everyday tasks above.
• Invoice Ninja Banking Integration — shows the bank side of matching incoming transfers to open invoices.

None of these require you to learn the admin UI’s corners. Type the request, watch the agent work, and ask it to explain anything it did. If you do not have a server yet, start here: Invoice Ninja on OpenSysLab.