Who owes us money, how late are they, and who do we chase first?

Six invoices and one credit at Northbrook Trading on 30 September

Northbrook Trading sends invoices to its customers and works in US dollars. Firms that get payment after delivery, for example by invoice, are more likely to report slow-paying customers¹. The as-of date is Wednesday 30 September 2026. For each invoice, the skill calculates the days past due: the as-of date minus the due date. Then it puts each invoice in a band of lateness. Accountants call these bands aging buckets.

Why sort by age? An older unpaid balance is less likely to be paid. Accountants use the same buckets to estimate the amount that will never come in. They apply a higher rate to the older buckets². The skill builds the aging only. It does not estimate that amount, and it never writes off a balance.

The oldest invoices are missing from a quick search

Most accounting systems have an invoice search. Most invoice searches show recent dates by default. So old unpaid invoices can be missing from the result. Those are the invoices that collections must chase.

The skill also ages each invoice on its open balance. Crestline paid 3,600 of a 10,000 invoice, so 10,000 − 3,600 = 6,400 is still open. The aging totals use 6,400. The detail shows the original 10,000 beside it.

A customer balance report does not replace an aging. It gives one total for each customer and no buckets, so it cannot show what is overdue.

The summary agrees, and the books show $750 more

The skill adds the invoices and the credit: 69,400 − 1,200 = 68,200. It compares that net total with the aging summary report, for each customer, for each bucket and in total. The two agree within 0.01. Accountants call this a summary-to-detail reconciliation.

Then it compares the 68,200 with the A/R balance on the balance sheet, which is $68,950. The difference is 68,950 − 68,200 = $750. A likely cause is a journal entry that someone posted directly to the A/R account. The skill puts the $750 on the Exceptions sheet, with the amount and the likely cause. It never forces the two figures to agree.

Two thirds of the money is late

The weighted days past due: (12,000 × 15 + 8,500 × 60 + 6,400 × 102 + 24,200 × 0 + 15,000 × 152 + 3,300 × 30) ÷ 69,400 = 3,721,800 ÷ 69,400 = 53.6 days. The skill counts Pinnacle's invoice as 0 days, so an invoice that is not yet due does not hide the late ones.

The skill also reports how much the five largest customers owe. Five Northbrook customers owe money, so the five largest are all of them. The largest one shows more: Pinnacle owes 35.5%. One customer that owes 40% of your receivables is a different risk from fifty customers at 2% each.

DSO means days sales outstanding: the average number of days that you wait for payment. The skill divides the ending A/R by the credit sales of the period, then multiplies by the days in the period. An accounting textbook also uses credit sales³. It divides net credit sales by the average A/R, and then divides 365 by that result. The skill uses the ending A/R and the days in the period. So the two formulas can give different results. With both formulas, fewer days usually means that customers pay faster³.

Two reminder drafts, and four customers with a different next step

The skill ranks the late customers by age and open balance. It sends a disputed invoice and an insolvent customer to a different path. Then it gives each customer a band of action.

Summit Hotels sent an insolvency notice. The skill stops ordinary reminders to Summit and sends the account to professional review. In the US, a bankruptcy filing usually starts an automatic stay. The stay stops lawsuits, garnishments and most collection activity against the debtor⁴. That rule is US law. Other countries have their own rules, so ask a professional about the countries where you trade.

Acme Corp disputes its invoice. The invoice stays in its bucket, and the skill routes it to the person who owns the dispute. A reminder that treats a disputed invoice as late damages the relationship and does not get the invoice paid.

The skill writes two drafts, for Crestline and for Harbor. Each draft is neutral and contains no fees or threats. Each draft carries the mark REVIEW REQUIRED - NOT SENT. The skill never contacts a customer. A person reviews each draft and decides whether to send it.

Seven items, in one message

The skill asks these first, in one short batch. It asks only for what it cannot already see. At item D, it makes a statement and asks no question.

1. Use MosoFin for this run, or upload the data yourself?
   MosoFin is the connection to your books and the other platforms you link. With it, the skill reads from there. Without it, you upload the files, and the checks are the same. The skill asks this only if your account has the MosoFin tools. If not, it says once that the run is manual.
2. As of which date?
   The skill counts every bucket from this date. It asks only if the date is not clear. It never chooses a default date without telling you.
3. What do you need: the aging only, a collection plan, DSO or reminder drafts? All customers, or one?
   The answer decides which inputs matter. The core aging needs no dispute flags, payment history, DSO or policy. For one customer, the skill finds the name in your customer list and tells you the match.
4. It tells you: an aging lists unpaid invoices, so it is always on invoices issued (accrual), even if you file on a cash basis.
   Only DSO and income figures depend on the basis. If you ask for a cash-basis aging, the skill explains this. Then it asks if accrual is acceptable, before it reads any data.
5. For DSO: the period. On the upload path, also your credit sales.
   Only if you want DSO. Credit sales are the base that DSO needs, because total income includes cash sales. On the MosoFin path, the skill calculates credit sales from invoices less credit memos. It offers the total-income proxy only with your approval.
6. Any disputes, credit holds, customer tiers or payment history?
   These change the ranking and the tone. Disputes go to resolution, away from collection pressure. The skill asks only when the plan needs them. It never guesses them from the ledger.
7. Your collection policy: approved wording, payment contact and escalation steps.
   Only if you want drafts. The drafts use only the terms that you supply. They use neutral language with no fees or threats.

Then it reads the plan back and waits for your yes. The skill's own example is for Northbrook. With DSO added for this page, it reads like this:

"Building the A/R aging for Northbrook Trading as of 30 September 2026, accrual basis, from your Mosofin connection: invoice detail tied to the aging summary, then a collection plan and reminder drafts in your approved wording, every draft marked not sent. DSO for July to September, on credit sales from your invoices and credit memos. Shall I go ahead?"

Connect once, or upload the aging detail

Seven sheets, from the run context to the coverage

It asks whether you want the sheets as an Excel file before it makes one. If you say no, you get the same sheets as tables in the chat. It waits until you see and approve the results. Then it offers to save your customer tiers, standing holds and disputes, collection policy and DSO basis for the next run. It never saves customer contact details, balances or draft letters.

Seven terms, in plain English

Accounts receivable

The money that customers owe you for invoices that they have not paid yet. Accountants write A/R or AR.

Aging

A table that sorts every unpaid invoice by how late it is.

Aging bucket

One band of lateness, for example 1-30 days late. The skill's default bands go from Current to Over 120.

Open balance

The part of an invoice that is still unpaid, after payments and credits.

DSO

Days sales outstanding: the average number of days that you wait for payment³.

Dunning

The routine series of payment reminders to a late customer.

Automatic stay

In the US, a bankruptcy filing usually starts it. It stops most collection activity against the debtor⁴.

Where the facts on this page come from

The sources are a Federal Reserve survey, two sections of an accounting textbook and a US courts glossary. We found each one on 28 October 2026 in search results. We did not open the pages, so follow each link for today's wording. What the skill does comes from the skill's own files.

1. Federal Reserve Banks: 2024 Report on Payments, Small Business Credit SurveyAbout four in five small firms have a problem with payments. Firms that get payment after delivery, for example by invoice, are more likely to report slow-paying customers.
2. OpenStax: Principles of Accounting, Volume 1, 9.2 Account for Uncollectible Accounts Using the Balance Sheet and Income Statement ApproachesThe aging method sorts receivables into age bands. It applies a higher rate of loss to the older bands, because older balances are more likely to stay unpaid.
3. OpenStax: Principles of Accounting, Volume 1, 9.3 Determine the Efficiency of Receivables Management Using Financial RatiosReceivables turnover is net credit sales divided by average receivables. Days' sales in receivables is 365 divided by that turnover. Fewer days usually means that customers pay faster.
4. Administrative Office of the U.S. Courts: Glossary, "Automatic stay"A bankruptcy filing usually starts an automatic stay. The stay stops lawsuits, garnishments and most collection activity against the debtor. This is a US rule.

No outside authority backs the six buckets, the action bands, the 0.01 tolerance, the seven sheets or the draft mark. They are the skill's own rules. We made up Northbrook Trading and every figure in the example for this page. All four sources are US sources.