What are the published limits on the Payables Agent?

Microsoft publishes them as a list, and it is short. PDF attachments only · ten per email · no PDF over ten pages or five megabytes · daily caps on emails and invoices. Two whole capabilities are named as unsupported. That list decides whether the agent fits your accounts payable — before any configuration question does.

What actually gets through to the agent?

Six constraints, all from Microsoft's own limitations section:

Emails without a PDF are not silently dropped. Microsoft: they "are not processed for invoice creation" and "appear as agent tasks that require manual attention." So the work still arrives — it arrives as a task for a person.

The attachment cap has a sharp edge worth knowing. An email with eleven attachments is not partly processed. "The agent skips emails with more than 10 attachments" — the whole email, not the eleventh file. A supplier who batches a month of invoices into one message hits this immediately.

And each PDF becomes its own unit of work: "Each PDF document found in an email becomes an entry in Inbound E-Documents… A distinct agent task processes each entry." That is also why the per-document metering works the way it does — the event breakdown is published per document.

What does the agent refuse to do?

*Two capabilities, named by Microsoft under its own Feature limitations heading:*

Approval flows · Anomaly detection

This is a published limitation list, not a search that found nothing — which is the strongest form this kind of claim takes.

Both absences matter more than they read. An accounts payable process without approval routing is not an accounts payable process in most organisations, so the approval step has to live somewhere else — Business Central's own workflow engine, with its own events and responses. And anomaly detection is the control most people assume an AI feature includes: the agent extracts and matches, it does not flag the invoice that is subtly wrong.

The agent also does not post. Microsoft's flow ends at a purchase invoice — the drafts are reviewed "so invoices are ready for approval and posting." Ready for, not posted.

Where does it stop and hand back?

At the vendor, and the stop is deliberate.

If it cannot identify the vendor confidently, the agent halts and asks a supervisor. A supervisor can instruct it to create the vendor from the extracted details — and Microsoft is careful about what happens next:

"When the agent creates a new vendor, the Blocked field on the vendor card is set to All… leaving the newly created vendor in a blocked state ensures no invoicing processing can happen until the vendor is unblocked."

And it says plainly why: "vendors and their bank accounts are approved by having communication with the vendor and doing human callbacks to the vendor's finance department. In many places, this action is a requirement for a successful audit."

Read that as a design principle, not a quirk. Counterparty-supplied data is not trusted by default. The agent will create the record and then refuse to let it transact until a person has done something outside the system.

Microsoft states the boundary flatly: "The agent itself doesn't provide any capabilities for vendor approvals."

Why does the mailbox setup matter so much?

Because the mailbox is the trust boundary, and Microsoft treats it that way.

"We recommend you use a shared mailbox that you keep as an internal-only mailbox and don't expose this mailbox to your vendors… by not exposing invoices to vendors, your employees become the first to review and identify potential fraud."

Three operational rules follow, all published:

• "The monitored mailbox should only be attended from within Business Central."
• "Users shouldn't access the monitored mailbox from Outlook."
• Do not share it with another agent — "If other agents, like the Sales Order Agent, use the same mailbox, it can cause conflicts with ownership of incoming emails."

The second rule is the one that breaks quietly in practice. An email a person has already opened in Outlook is an email the dispatcher may not pick up — and nothing tells you the invoice was missed, because from the agent's side nothing happened.

So does it fit your accounts payable?

Answer four questions about your own mail, in this order, before anything else:

1. Do your suppliers send PDFs? If a meaningful share send links, portals or spreadsheets, those invoices arrive as manual tasks regardless of how the agent is configured.
2. How long is a typical invoice? The page cap is the limit most likely to bite a construction, logistics or professional-services supplier with itemised backup.
3. Does anyone batch? One supplier attaching a month of invoices to a single email is skipped entirely.
4. Where does approval live today? It cannot live in the agent, so it has to live in a workflow, and that is a separate design decision.

Those four answers decide fit. Everything else — permissions, profiles, supervisors — is configuration, and configuration only matters once the documents can actually get through.

And the limits are worth reading as a family rather than one at a time. Where all the built-in agents stop is the same exercise across Sales Order, Payables and Expense, and the pattern is more useful than any single cap.

About Cognilium Cognilium builds AI optimization apps for Microsoft Dynamics 365 — companion apps that optimize the pricing, inventory, warehouse and planning decisions your ERP manages but can't optimize. Dynamics is your system of record. Cognilium is your system of intelligence. https://cognilium.ai · https://www.linkedin.com/company/37180269/

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Run the four questions above against one month of your own supplier mail. Bring the answers to a 15-minute call and we will tell you where the agent fits and where it does not.

Sources

• Payables Agent Overview — Business Central · ms.date 2026-05-03, updated 2026-07-08