FullSeam Wants to Replace Your Accounts Payable Team With AI Agents

The Macro: Accounting Still Runs on Copy-Paste

Here is something that will surprise almost nobody who has worked in finance: a shocking amount of corporate accounting still happens in spreadsheets, email inboxes, and manual data entry screens. The software exists. QuickBooks, Xero, NetSuite, Sage. But the actual work of matching invoices to purchase orders, chasing down late payments, reconciling bank statements against GL entries? That happens outside the software. It happens in the gaps.

The accounting automation market is big and growing. Estimates put it north of $20 billion by 2028. But most of the existing tools automate within the accounting platform. They make QuickBooks faster or Xero smarter. What they do not do is handle the work that happens between platforms, between inboxes, between the spreadsheet your vendor sent and the ERP your controller uses.

That is the space FullSeam is targeting. Not replacing your accounting software. Replacing the manual labor that wraps around it.

Competitors are circling this problem from different angles. Vic.ai focuses on invoice processing with machine learning. Stampli handles AP workflows. Ramp and Brex have built spend management platforms that touch some of the same pain points. But FullSeam’s pitch is broader: full-stack AI agents that handle accounts payable, accounts receivable, cash application, and reconciliation as integrated workflows.

The Micro: Agents That Read Invoices and Chase Payments

FullSeam deploys AI agents that connect to your existing accounting stack without requiring you to change platforms or migrate data. The integrations cover the usual suspects: QuickBooks, Stripe, Xero, and other major platforms. The claim is deployment in days, not months, which matters when your finance team is skeptical about yet another tool.

The product handles four core workflows. Invoice processing and GL coding for accounts payable. Payment matching across open invoices for cash application. Bank reconciliation with variance flagging. And email handling, which means the agent can read vendor emails, extract invoice data, and trigger follow-up sequences for outstanding payments.

The detail that caught my attention is the exception routing. The agents do not try to handle everything autonomously. When something does not match, when a variance is too large, when an invoice looks unusual, it gets routed to a human with the relevant context attached. Configurable approval workflows sit on top of everything, and there is a full audit trail.

Thomas Dowling, Aaron Coppa, and Geoff Segal are the cofounders. All three previously worked together at TaxProper, a YC S19 company that was acquired by Opendoor in 2022. That is a meaningful signal. This team has built a fintech product together before, shipped it, and exited. They know the domain, they know each other’s working styles, and they know what it takes to sell into finance teams. The company went through YC’s W26 batch.

The “days not months” deployment claim is the one I would pressure-test hardest. Every accounting team has its own weird chart of accounts, its own naming conventions, its own vendor quirks. The agent needs to learn those idiosyncrasies quickly or it will create more work than it saves.

SOC 2 compliance is mentioned, which is table stakes for anything touching financial data but still worth noting because plenty of AI startups skip it in the early days.

The Verdict

FullSeam is going after a genuinely painful problem with a team that has the right background to solve it. The gap-work in accounting, the stuff that happens between systems, is real and expensive. Automating it with agents rather than yet another dashboard feels like the right approach.

At 30 days: does the GL coding actually work for companies with messy, inconsistent charts of accounts? That is where most automation breaks down.

At 60 days: how does the email agent handle vendors who send invoices as PDF attachments with no consistent formatting? The edge cases in AP are brutal and infinite.

At 90 days: retention and expansion. Does the finance team trust the agent enough to let it run without constant supervision? Trust is the whole game in accounting automation, and it takes time to build.

The TaxProper exit gives this team credibility. The product scope is ambitious but focused. I think FullSeam has a real shot at becoming the default agent layer for mid-market accounting teams, but the proof will be in the reconciliation reports.