Use Case

AI Invoice Processing and AP Automation

Accounts payable teams spend most of their time on data entry and exception handling that AI handles better and faster. We build end-to-end invoice automation that cuts AP cost per invoice while improving accuracy and audit readiness.

The Challenge

At a typical $500M distributor, AP clerks spend 10-14 hours a week on 3-way matching between the ERP, a separate vendor portal, and an Outlook inbox where suppliers still email PDFs. Invoices arrive in 40+ formats across hundreds of vendors. Each one needs header and line extraction, PO match, tax validation, GL coding, and approval routing. The team rejects 6-8% of invoices for discrepancies that are usually just vendor SKU-naming variances or unit-of-measure mismatches. Cost sits at $10-25 per invoice, and 20-30% of early-pay discounts are missed because the cycle is too slow. Month-end is worse. A contract rate of 3-5% error rate on keyed invoices is the baseline most AP directors accept, because the work is too repetitive to stay sharp on.

Our Approach

A Claude Sonnet 4.5 agent reads incoming invoices from an SFTP drop, an O365 shared mailbox, and EDI feeds, then extracts header and line items via structured output. It queries SAP S/4HANA for matching POs using the vendor ID and PO reference, applies your tolerance rules (price, quantity, unit of measure), suggests GL codes from historical coding patterns stored in a Postgres feature store, and posts approved entries via SAP OData APIs. Exceptions route to a review UI that mirrors an Excel grid, with the failed validations highlighted inline. The agent learns from every reviewer override through a feedback loop that updates vendor-specific extraction prompts and coding rules. Sonnet 4.5 handles vendor-specific layout drift without retraining, which is where rules-based OCR pipelines fail.

How We Do It

1

Invoice Capture and Data Extraction

The agent monitors an O365 shared mailbox, an SFTP drop, and vendor portal APIs on a 5-minute poll. Attachments flow through Textract for the PDF image layer, then Claude Sonnet 4.5 extracts header fields (vendor, invoice number, dates, totals, tax, PO reference) and line items (description, SKU, quantity, unit price, line total) as structured JSON. Accuracy is validated against a golden set of each top-50 vendor's formats during onboarding. Failure mode: OCR quality drops below 85% confidence on a scanned fax, in which case the invoice routes to manual keying with the raw image attached so nothing stalls silently.

2

PO Matching and Validation

Extracted data is matched against open POs in SAP using a composite key of vendor ID + PO number, with fallback to fuzzy match on vendor name when the PO number is missing or malformed. 2-way match covers services, 3-way match adds goods receipt verification. Tolerance rules (e.g. 2% price variance, 5% quantity variance up to $500) are configurable per category. Discrepancies surface with specifics: 'Line 3 price variance +4.2%, expected $42.10, got $43.87'. Failure mode: vendor SKU differs from PO SKU (14A-BOF vs 14A-BOE). The agent checks the vendor cross-reference table before flagging.

3

GL Coding and Cost Allocation

For each line item, the agent queries a Postgres vector index of the last 24 months of coded invoices from that vendor and line description. If it finds 10+ matches with 90%+ coding agreement, it auto-codes with the majority GL account and cost center. Otherwise it suggests the top 3 codes with confidence scores for reviewer pick. New vendors default to a coding queue with the category lead. Failure mode: a vendor switches business lines mid-year and historical coding no longer reflects intent. The system's drift monitor flags when the top coding shifts and routes the next 10 invoices to review.

4

Approval Routing and ERP Integration

Validated invoices route to approvers from your delegation-of-authority matrix, looked up by cost center, amount band, and vendor category. Approvers receive a Teams card with the invoice PDF, the extracted fields, and one-click approve or reject. On approval, the agent posts to SAP via the A/P invoice OData endpoint, captures the document number, and writes a signed audit entry to an append-only Postgres log. Failure mode: SAP returns a posting error (duplicate invoice, closed period, budget block). The agent catches the response code, routes to AP with the exact SAP error text, and retries once the block is cleared.

What You Get

Invoice processing cost drops from $15-25 per invoice to under $3 for straight-through processing
90% of invoices with valid PO matches process without human touch within 60 days of go-live
Early payment discount capture increases 35%, typically worth $400K-$1.2M annually for mid-market buyers
75% faster month-end close as AP backlog clears daily instead of in a week-end sprint
Audit preparation time drops 60% because every decision has a signed, searchable trail exportable as CSV

Where this fits — and where it doesn't

Good fit when

  • High-volume, repetitive AP environments with 3,000+ invoices monthly across 100+ vendors, where per-invoice processing cost is a measurable line item and the AP team is understaffed relative to volume.
  • Organizations running a mainstream ERP (SAP, Oracle, NetSuite, Dynamics) with documented PO data, clean vendor master records, and APIs already enabled for A/P posting.
  • Companies where at least 70% of spend flows through POs, giving the agent a reliable match anchor. Non-PO spend can still route through coding rules but accuracy is lower.

Not a fit when

  • ×Vendor master data is a mess. If the vendor file has duplicate records, inconsistent naming, and no PO discipline, the agent will compound the existing chaos rather than fix it. Clean the master first.
  • ×Highly custom, hand-keyed invoice formats with freeform descriptions and no PO reference, common in construction progress billing or professional services retainers. These are better suited to a guided intake form than agent extraction.
  • ×Organizations with fewer than 500 invoices monthly. The per-invoice cost savings don't cover implementation and the team loses more by context-switching than they gain in automation.

Technology Stack

Claude Sonnet 4.5AWS TextractSAP Integration SuiteOracle REST APIsApache AirflowPostgreSQLpgvector

Integrates with

SAP S/4HANAOracle Fusion CloudNetSuiteMicrosoft Dynamics 365 FinanceQuickBooks OnlineBill.comCoupaWorkday Financials

Related Services

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Industries We Serve

Frequently Asked Questions

What ERP systems do you integrate with for invoice processing?+
We integrate with SAP S/4HANA, SAP ECC, Oracle Fusion Cloud, Oracle EBS, Microsoft Dynamics 365 Finance, NetSuite, Workday Financials, and QuickBooks Online. Integration complexity depends on your specific configuration and which APIs your IT team has enabled. SAP S/4HANA with OData endpoints is the most common path. Oracle EBS often requires an intermediate integration platform. NetSuite uses SuiteTalk REST. We scope the specifics during discovery, including which fields are required on the A/P document, which tax determination method is in use, and how approval hierarchies resolve. Most integrations land in a 3-4 week window.
How does the system handle invoices from vendors who don't use a standard format?+
Claude Sonnet 4.5 handles format variability without per-vendor templates. For a new vendor with no prior processing history, the agent attempts extraction and routes the result to a human reviewer with the raw document side-by-side. The reviewer corrects any errors, and the agent writes that vendor's quirks (non-standard date format, line items in the footer instead of a table, tax as a percentage rather than a dollar amount) to a vendor-specific prompt fragment used on subsequent invoices. After 3-5 corrected invoices, most vendors process at 95%+ straight-through. There is no requirement for vendors to change their formats.
What is the straight-through processing rate we should expect?+
For invoices with valid PO references and no discrepancies, straight-through rates run 80-90% after 60 days of operation on a representative vendor mix. The remaining 10-20% involve genuine exceptions: price or quantity variances above tolerance, new vendors, invoices without PO references, or invoices where the vendor has changed their remit-to address. These are real exceptions that should involve human review, not system failures. We track straight-through rate weekly and work with AP leadership to identify systemic exception causes (a specific vendor with consistent tolerance issues, a cost center with stale POs) that can be addressed at the source rather than in AP.
How does the agent handle edge cases it hasn't seen before?+
Every invoice that scores below a configurable confidence threshold (typically 85%) routes to human review with the agent's best extraction pre-populated and the specific low-confidence fields highlighted. The reviewer either confirms or corrects. The correction writes back to the agent's memory for that vendor. The system never posts a decision it is not confident in. For a genuinely novel edge case, the first time it appears the agent flags it, a human resolves it, and the resolution informs future handling. The design assumes exceptions will always exist and builds the review path as a first-class workflow rather than an error condition.
What happens when the agent is wrong?+
Wrong can mean three things. First, an extraction error caught in validation: the invoice totals don't foot, a date is invalid, a PO number points to a closed PO. These never reach posting because the validation rules block them. Second, an extraction error that passes validation but is caught on approval: the approver rejects, the reasons are logged, and the vendor-specific prompt is updated. Third, an error that reaches posting: the system creates an audit entry that supports a reversing entry in the ERP and an alert to AP leadership. Across our deployments, type-three errors run under 0.3%, lower than the manual baseline they replace.
How do we audit every decision?+
Every agent action writes an entry to an append-only Postgres log: invoice ID, timestamp, input payload, extracted fields, PO match result, GL coding decision, approver, posting document number, and a hash chain to prevent tampering. The log exports to CSV or straight to your audit tool (AuditBoard, TeamMate, Workiva) via scheduled push. For SOX-scoped controls we configure dual-control on any coding override above a threshold and produce a quarterly attestation report automatically. External auditors have access to the same log your internal team does. Most auditors we've worked with prefer this trail over manual paper documentation because it answers sampling questions in minutes.
What's the upfront data prep we need to do?+
Three things, in order of impact. First, vendor master cleanup: deduplicate vendor records, validate remit-to addresses, confirm tax IDs. The agent is only as good as this data. Second, 24 months of historical coded invoices as a training signal for GL coding patterns. We can pull this from your ERP directly if you can grant read access. Third, a documented tolerance matrix: what price variance is acceptable by category, what quantity variance, what approval bands per amount. Most AP teams have this informally; we formalize it. Budget 2-3 weeks for this prep work in parallel with technical integration. Skipping it doesn't break the system but it reduces straight-through rates by 15-25 points.
How long to production?+
A focused deployment covering your top 50 vendors and one ERP entity runs 8-10 weeks from kickoff to first production invoice. Weeks 1-2 are discovery and data access. Weeks 3-5 build the extraction, matching, and coding pipeline on a dev environment using historical invoices. Weeks 6-7 run a shadow mode where the agent processes live invoices in parallel with the manual team, and accuracy is compared daily. Weeks 8-10 are cutover: the agent processes production invoices with tight monitoring. Full coverage across all vendors and entities typically takes another 8-12 weeks. We don't recommend a big-bang rollout. Phased cutover by vendor tier gives the team time to calibrate.

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