A plain-english guide

Your books and billing, run by an assistant

Two free programs cover the two halves of a service business — getting paid, and keeping the books. An AI assistant can operate both of them for you. You talk; it does the clicking.

The idea in one minute

Every small business has two money jobs. One: send quotes and invoices and actually collect the money. Two: keep track of what came in, what went out, and what you made — the books, the stuff that matters at tax time.

There's a well-made, free program for each job. And because both can be operated by an AI assistant, you don't have to learn either one deeply. You ask for what you want in normal words — “send Dave his invoice,” “what did I clear last month?” — and the assistant goes and does it in the right program.

The two programs

Money in

Invoice Ninja

Your front counter. Quotes and estimates, invoices, recurring monthly billing, collecting payment (it plugs into Stripe or PayPal), your client list, and automatic “you're overdue” reminders. If you bill for your time, it tracks hours and turns them into an invoice.

Money out & the books

Firefly III

Your back office. Every dollar in and out, sorted into categories. Budgets, recurring bills, and clear reports — profit & loss, where your money goes, how much cash you have. This is the part that makes tax time painless.

How they work together

Think of it as one loop. Invoice Ninja handles the customer and the getting-paid part; Firefly keeps the running record of your business's money. The assistant is what connects them.

1Quote a job & send an estimate — Invoice Ninja
2Customer says yes → turn it into an invoice & collect payment — Invoice Ninja
3That income, plus your expenses, get recorded in the books — Firefly III
4Each month the books tell you what you made, spent, and owe — Firefly III

What the assistant can do

Assuming you give it full access, here's the reach — everything you could do by clicking, it can do by being asked.

With your billing

  • Write and send estimates and quotes
  • Turn an accepted quote into an invoice and send it
  • Set up recurring monthly invoices (retainers)
  • Record payments and see who's paid vs. unpaid
  • Chase overdue invoices with reminders
  • Manage your clients, services, and pricing
  • Track billable hours and bill them
  • Pull a “who owes me money” report

With your books

  • Record income and expenses
  • Sort everything into the right categories
  • Set budgets and flag when you're over
  • Match up bank and card activity
  • Answer “what did I make after expenses?”
  • Produce a profit & loss and spending reports
  • Track savings goals
  • Hand your accountant clean numbers at tax time

And the part that ties it together

Because it runs both, the assistant can take a job from quote all the way to booked income — and answer questions that cross both programs, like “how much did I actually clear last month, and who still owes me?”

Mostly, you just talk to it

You don't open menus or learn screens. You say what you want:

“Send Dave an estimate for the June cleanup — 12 hours at my usual rate.”
“Anyone unpaid past 30 days? Send them a friendly reminder.”
“How much did I actually make last month after expenses?”
“Set up a monthly invoice for the Miller retainer.”
“Categorize this week's card charges and tell me if I'm over on fuel.”

The honest limits

—

It's not your accountant. It organizes everything and makes tax time easy, but a real person still files your taxes. Think of it as the world's most organized bookkeeper, not the CPA.

—

US bank auto-import is hit-or-miss. Some banks connect live; many don't. In practice you may drop in a spreadsheet from your bank or Stripe now and then instead of a live feed. Minor, but worth knowing.

—

Full access means it can change real records. That's the point — but early on it's smart to have it “draft it and let you okay it” for the bigger moves, until you trust how it works.

—

It's your data, on your machine. Nothing lives in someone else's cloud unless you choose that. The flip side: it needs to be backed up and kept updated — which can be set up once and left alone.

What it takes to set up

Both programs run on a computer you control — even a Mac. Each one gets a small connector that lets your assistant operate it, and after that it's just conversation.

The one choice that affects the setup: a desktop assistant (living on your computer) is the simplest and most private — everything stays local. A cloud assistant works too, but needs a little extra plumbing so it can reach the programs on your machine safely.

Either way it's a one-time setup that someone does for you. From then on, you're just asking for what you need.