Stampli Review 2026: AI Invoice Approval Software Tested

What Stampli does

Stampli is an invoice approval and AP automation platform. Its core differentiator is Billy the Bot — an AI assistant that learns your GL coding patterns and automatically suggests account codes, cost centres, and project codes when a new invoice arrives.

Over time, Billy the Bot learns from your team's corrections and approvals, improving coding accuracy. Most Stampli customers report 70–85% auto-approval rates for routine invoices after 60–90 days of use — meaning the coding suggestion is accepted without modification.

Stampli integrates with 70+ accounting platforms and ERPs: SAP, Oracle, Microsoft Dynamics, Sage Intacct, NetSuite, QuickBooks, and Xero. This breadth is rare — most AP tools support 3–5 platforms.

How the AI coding works in practice

When a vendor invoice arrives in Stampli (via email, PDF upload, or vendor portal), Billy the Bot reads the invoice, identifies the vendor, and suggests GL codes based on how your team has coded similar invoices from that vendor in the past.

For a new vendor, Billy makes an educated initial guess based on invoice content and similar vendors. The approver reviews, corrects if needed, and approves — and that correction feeds back into Billy's model. By the third or fourth invoice from the same vendor, the auto-suggestion is usually correct.

The result: finance staff spend less time on routine coding decisions and more time on exceptions. Controllers report that Stampli shifts their role from data entry to exception management — a meaningful quality-of-work improvement at scale.

Pricing and implementation

Stampli does not publish pricing publicly. Based on user reports and industry data, pricing typically ranges from $500 to $2,000+/month depending on invoice volume, number of ERP integrations, and number of users. Most mid-market implementations fall in the $800–$1,500/month range.

Implementation takes approximately 1 month for standard setups and 8–12 weeks for complex ERP configurations. Stampli provides a dedicated implementation team — unlike BILL or Ramp, which are largely self-serve, Stampli's complexity requires guided onboarding. Budget a full month of internal involvement for standard implementations: getting approval workflows, GL coding rules, and ERP field mapping right takes meaningful back-and-forth.

What real users say: G2 shows 4.6/5 across 1,925 verified reviews — the highest review volume for a pure AP automation platform. Implementation support receives consistent praise: Stampli's customer success team is rated as responsive and hands-on during setup. Two recurring complaints in 2024–2025 reviews: (1) Pricing opacity — every quote requires a full sales process, which is friction for teams that want a quick cost estimate; (2) Q4 2024 UI regression — multiple verified G2 reviewers flagged that a Q4 2024 platform update broke AI-suggested line items on multi-line invoices, requiring manual re-entry until the fix was deployed. Stampli resolved this in Q1 2025, but the complaint cycle shows that AI features can regress on platform updates — relevant to consider when the AI coding is the primary reason for purchasing.

Stampli vs BILL: when to choose which

BILL is the right choice for SMBs (under 100 employees) that primarily use QuickBooks Online or Xero and want a reliable, lower-cost AP solution. Stampli is the right choice for mid-market companies (50–500 employees) that need AI coding assistance, broader ERP support, or three-way matching.

The price gap is significant: BILL at $79/user/month for a 3-person AP team is approximately $237/month. Stampli for the same team might be $1,000–$1,500/month. The premium is only justified if your team spends 10+ hours per week on manual invoice coding — at that point, Stampli's automation pays for itself.

Verdict: who should use Stampli

Stampli is the right choice for mid-market companies processing 100+ invoices per month that have outgrown BILL's approval depth, need to integrate with a non-standard ERP, or want AI-assisted coding to reduce manual GL work.

It is not the right choice for small businesses under 50 employees or under 50 invoices/month — the cost-to-value ratio does not work at lower volumes. For those businesses, BILL or even QuickBooks Bill Pay is the more practical choice. For a full alternatives comparison, see our Stampli alternatives guide.