AI Workflows to Extract and Process Invoices Automatically

# Automated Invoice Processing Workflow for Construction AP

## 1. Recommended Tool Stack

- **Ingestion:** Dedicated inbox (ap@yourco.com) + Google Drive/SharePoint folder for scanned paper invoices
- **OCR/AI Extraction:** **Nanonets** (strong on construction invoices, line items, and handwritten PO numbers) — alternative: Rossum or Docparser
- **Workflow Orchestrator:** **Make.com** (best price/power for 600 invoices/mo) — alternative: n8n if self-hosted
- **Approval Layer:** **Approval flows in Make** + Slack/Email, or **Pipefy/Kissflow** for richer PM dashboards
- **Accounting System:** **QuickBooks Online** (native Make connector)
- **Storage/Audit:** Google Drive or Dropbox with a structured folder per vendor/project

## 2. Workflow (8 Steps)

1. **Ingest** — Make watches `ap@yourco.com` and the "Scanned Invoices" Drive folder. Every new PDF triggers the scenario and is archived to `/Invoices/Inbox/{YYYY-MM}`.
2. **Extract with Nanonets** — PDF is sent to a trained Nanonets construction model, returning JSON with header + line-item data and a confidence score per field.
3. **Vendor & PO Matching** — Make queries QuickBooks for the vendor (fuzzy match on name/EIN) and checks the invoice's PO/job number against an active projects table (Airtable or Google Sheets).
4. **Validation Rules** — Auto-check: totals = sum(lines) + tax, duplicate invoice # per vendor, date within 90 days, confidence > 85%. Failures route to an "Exceptions" queue in Airtable.
5. **Approval Routing** — Based on job code, Make notifies the assigned Project Manager via Slack/email with a preview link and Approve/Reject/Edit buttons. Thresholds: <$1K auto-approve if PO-matched; $1K–$10K single PM approval; >$10K PM + Controller.
6. **Post to QuickBooks Online** — On approval, Make creates a Bill in QBO with vendor, job/class, expense account, line items, and attaches the original PDF.
7. **Confirmation & Filing** — Invoice moved to `/Invoices/Posted/{Vendor}`; status written back to Airtable log; Slack confirmation to submitter.
8. **Exception Handling** — Unmatched vendors, low-confidence extractions, or rejected approvals flow to an AP staff review board in Airtable with the raw PDF, extracted fields, and a "Fix & Resubmit" action that retrains Nanonets.

## 3. Key Fields to Extract

- Vendor name, address, EIN/tax ID
- Invoice #, invoice date, due date, payment terms
- PO number / **Job or project code** (critical for construction)
- Line items: description, quantity, unit price, cost code
- Subtotal, sales tax, retainage, total due
- Remit-to address / ACH details

## Risks to Monitor

1. **Duplicate payments** — Enforce unique (vendor + invoice#) check before QBO posting.
2. **Job cost miscoding** — Low-confidence job codes should always route to PM, never auto-post, to protect project profitability reporting.
3. **Fraudulent remit-to changes** — Flag any vendor whose bank/ACH details differ from the last posted invoice for manual verification.

**Expected impact:** ~20 of 25 weekly AP hours recovered; 2–3 day faster approval cycle.

# Automated Invoice Processing Workflow for Construction AP

## 1. Recommended Tool Stack

| Component | Tool |
|-----------|------|
| **OCR/AI Extraction** | Nanonets (construction-friendly, handles poor scans) |
| **Workflow Orchestrator** | Make (formerly Integromat) – intuitive, cost-effective |
| **Accounting System** | QuickBooks Online (existing) |
| **Email & Storage** | Gmail/Outlook + Google Drive or OneDrive |
| **Approval & Routing** | Slack (notifications) + simple approval web form |

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## 2. Automated Workflow (8 Steps)

**Step 1: Invoice Ingestion**
Email automation rule routes all vendor invoices to a dedicated inbox. Make monitors this inbox and downloads PDF/image attachments to cloud storage.

**Step 2: Document Classification & Extraction**
Nanonets OCR processes each document. AI model extracts: vendor name, invoice number, date, amount, line items, and custom field: "Project Code" (critical for construction).

**Step 3: Data Validation & Enrichment**
Make validates extracted data: checks for missing fields, matches vendor name against QuickBooks vendor list, and flags currency mismatches. Enriches with cost center/project from vendor history.

**Step 4: Duplicate Detection**
Make queries QuickBooks for invoices with matching vendor + amount + date within 5-day window to prevent duplicate posting.

**Step 5: Approval Routing**
Invoices route to project managers via Slack notification with extracted details and a clickable approval form (Google Form or Zapier embedded form). Invoices under $500 auto-approve; >$500 require PM sign-off. Approval decision stored in Make.

**Step 6: Three-Way Match (Optional Enhancement)**
If PO data is available, Make cross-references line items against purchase orders in QuickBooks (amount, quantity, description). Flags mismatches for manual review.

**Step 7: QuickBooks Sync**
Approved invoices are pushed to QuickBooks Online via the QBO API through Make:
- Creates bill with vendor, amount, invoice number, date
- Tags with project code/cost center
- Attaches original PDF to bill record

**Step 8: Exception Handling & Reporting**
Invoices failing validation or flagged for mismatches are sent to AP manager via Slack with a detailed exception report. Manual review updates invoice status. Weekly dashboard shows processing metrics.

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## 3. Key Fields to Extract

- Vendor name & tax ID
- Invoice number & date
- Amount (total & line-item detail)
- **Project Code** (construction-specific)
- PO reference
- Due date & payment terms

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## 4. Key Risks to Monitor

1. **OCR Accuracy on Poor Scans**: Handwritten invoices or low-quality PDFs cause extraction errors. Mitigation: Nanonets confidence thresholds trigger manual review for <85% confidence; set aggressive validation rules.

2. **Project Code Missing/Wrong**: Misassignment blocks accurate cost tracking and project profitability. Mitigation: Make project code mandatory; if blank or unmatched, route to PM for clarification before posting.

3. **Duplicate/Overpayment**: Same invoice processed twice or submitted by multiple vendors. Mitigation: Implement 5-day duplicate check + three-way match where PO data exists.

---

**Expected Outcome**: 80–90% of invoices process autonomously; AP staff shift from data entry to exception handling and vendor relationships. ROI in 4–6 months.

Here is a complete step-by-step automated invoice processing workflow design.

### **(1) Recommended Tool Stack**

*   **OCR/AI Extraction:** **Nanonets**. It has a robust pre-trained invoice model that works well with varied layouts seen in construction and can be easily trained on new formats.
*   **Workflow Orchestrator:** **Make (formerly Integromat)**

### (1) Recommended Tool Stack
- **OCR/AI Extraction**: Nanonets (AI-powered invoice parsing with 95%+ accuracy, handles PDFs/scans, QuickBooks integration).
- **Workflow Orchestrator**: Make (robust no-code automation for multi-step logic, email triggers, approvals; cheaper than Zapier for high volume).
- **Accounting System**: QuickBooks Online (native sync for bills/expenses).

### (2) Numbered Workflow (8 Steps)
1. **Ingestion**: Use Make to monitor company email inbox (e.g., ap@company.com) for new emails with PDF attachments; route paper scans via mobile app (e.g., Genius Scan) to shared Google Drive folder watched by Make.
2. **Pre-processing**: Make downloads PDFs/scans, converts to standardized format, and sends to Nanonets API for OCR.
3. **Data Extraction**: Nanonets extracts fields using pre-trained invoice model; auto-categorizes by vendor/project via custom ML rules (train on 50 sample invoices initially).
4. **Initial Validation**: Make runs rule-based checks (e.g., total matches line items, due date > invoice date); flags anomalies (e.g., amount > $10K) to AP Slack channel.
5. **Approval Routing**: For valid invoices, Make creates approval task in Asana/Trello assigned to project manager (based on extracted PO/project code); includes extracted data preview and PDF link; multi-level for high-value.
6. **Post-Approval Sync**: On approval, Make pushes bill to QuickBooks Online via API (maps fields to QB Vendors/Accounts/Projects); attaches PDF as document.
7. **ERP Confirmation**: Make confirms QB posting, notifies vendor via email (e.g., "Invoice received"), and archives files in Google Drive.
8. **Exception Handling**: Route extraction failures/low-confidence (<90%) or rejected invoices to AP queue in Airtable; auto-retrain Nanonets model weekly; alert on duplicates via QB hash check.

### (3) Key Fields to Extract & Risks
**Key Fields**: Invoice #, date, vendor name/address, total amount, due date, PO/job code, line items (description, qty, unit price, total), tax/subtotals.

**Risks to Monitor**:
- Extraction errors on handwritten/scanned invoices (mitigate: human review queue).
- Approval delays (monitor: SLA dashboards in Make).
- Duplicate postings (mitigate: hash-based deduping).

*(Total: 348 words)*