On Thursday afternoon the controller at a seventy-person precision machine shop prints the aging report. Thirty-eight open invoices past due. Invoice 4471 is forty days late because the customer's receiving clerk logged nine parts instead of ten, and the shop's quality manager is still arguing about the tenth. Invoice 4502 is thirty-five days late because the customer only pays invoices submitted through its supplier portal, and nobody in the office is sure that one was ever accepted. Invoice 4515 is twenty days late and the owner said last month to go easy on that customer until the next order lands. To the report those are three late invoices. The controller sees three different problems.
Chasing money is four jobs wearing one coat
Collections is four jobs, and they fail in different ways.
The first is knowing what is owed, which the accounting system does well. The second is knowing why it has not been paid, which the accounting system does not know at all, because the reason lives in a quality hold, an email from a receiving clerk, a portal status screen or the owner's head. The third is deciding what to do about each one this week: send a reminder, make a call, resubmit through the portal, issue a credit for the missing part, or leave it alone. The fourth is doing it, in words the customer recognizes as coming from your company and not from a dunning robot.
Why this is a build and not a purchase
The part of this job that matters runs on facts and rules that live in the shop and nowhere else. No product can know that the tenth part is on a quality hold, that the portal never confirmed invoice 4502, or that the owner wants one customer left alone until the next order lands. The reminder tools that attach to accounting software work from invoice age alone; nothing we found reads a quality hold or a portal status, and the rules about which customer gets a call and which gets patience are the shop's own, written nowhere. That is the test for any build: if the thing you would pay for runs on your data and your judgment, no vendor can sell it to you, because they have neither.
What would have to be built
The useful thing is smaller than a finance agent and more specific to the shop. It reads the open invoices from the accounting system the shop already uses, and beside each one it holds the facts the ledger does not: whether a quality hold or a receiving discrepancy is open on that shipment, whether the invoice went through the customer's portal and what the portal says about it, whether the owner has marked the customer hands-off, and when the last reminder went out and whether anyone answered.
Those facts exist somewhere in the building: on a whiteboard, behind three portal logins, in the owner's head. The build's first job is to give each a home a program can read: a note on the invoice, a column on the customer record, a mailbox the portal confirmations are forwarded to.
Its second job is the sorting. Every Thursday morning it puts the overdue list into four piles, remind, call, fix first, and leave alone, using rules the shop writes down: a customer with an open quality hold is not reminded until the hold clears, a portal invoice with no confirmation is resubmitted before anyone is called, a hands-off customer gets nothing. Its third job is the drafting: a reminder in the shop's own wording, with the invoice, PO and part numbers attached, waiting for the controller to send or change.
What the office looks like after: the controller opens one list on Thursday instead of three systems and a printout. The fix-first pile has the reason beside each invoice, so the call about the tenth part happens Thursday instead of the week the customer asks why. The leave-alone pile stays quiet, because the owner's instruction became a rule instead of a memory. Her afternoon goes to the five invoices that need judgment.
The genuinely hard part is not the program. It is the decision to record the reasons in one place, and the first month of keeping it up.
The category is moving, and where the vendors stop
Aion, which describes itself as a finance platform for growing businesses, says it has launched something called Aion Agent that handles billing and collections and submits invoices through Aion or directly in a customer's portal, with every payment waiting for a person to approve it. The account is Aion's own release as carried by CPA Practice Advisor on November 2, 2026; no independent reporting on it was found, so treat every claim as the company's. Aion says the agent was "available today to all Aion clients", which reads as generally available for its own customers; nobody outside Aion has confirmed that, and Aion's product page does not repeat it or name a price.
Where it stops is the point. The agent is built into the platform "where a company's money already moves", which reads as a business running its banking on Aion, and it works in portals "the way a person would" except, by Aion's own product page, on sites that block automated browsers, where a person clicks through. Neither the release nor the product page says how the agent decides which invoice to chase or when to stop, what the reminders say, or what happens to a short-paid or disputed invoice. Those are the reasons and the rules, and they are yours.
Who will resist, and why they are right
The controller will, and she should. Her Thursday list is the company's memory of every customer relationship, and the first version of anything that replaces it will send a polite reminder to the customer the owner said to leave alone. She will keep running her own list beside it for months and quietly override the drafts.
The outside sales rep will resist differently. He will not say anything, and he will keep telling his customers to ignore the automated notes and call him. He is right that a reminder sent on the wrong week can cost a reorder worth more than the invoice.
The honest no: below roughly forty open invoices at any one time, a Friday call list run by one person beats any build. And if invoices go out late, or without the customer's PO number, or outside the portal the customer requires, the chasing is not the problem. The invoicing is.
If this is your Thursday afternoon, the ten agent roles are in the Library.