n8n Bank Reconciliation Workflow: ERP Invoices + Slack

Automatically reconcile bank/PSP payments to ERP invoices—with Slack approvals

This n8n Bank Reconciliation Workflow connects your bank/PSP and ERP via HTTP APIs to match payments to open invoices. It automatically applies exact matches, routes partial matches to Slack for approval, logs outcomes in Google Sheets, and posts a reconciliation summary back to Slack.

What this workflow does

• Runs on schedule or manually and loads configuration values such as API URLs, matching tolerances, Google Sheets IDs, and Slack channels.
• Fetches incoming payment transactions from your bank/PSP API and open invoices from your ERP/accounting API.
• Compares payments to invoices using deterministic rules: it attempts a reference match first, then applies amount/currency plus a date window to classify each payment as matched, partial, or unmatched.
• Applies matched payments by updating the invoice in the ERP via an HTTP request, and appends the result to an audit log in Google Sheets.
• Handles partial matches by posting candidate invoices to Slack for human review, waiting for a decision, then either applying the payment in the ERP and logging it—or flagging it as a rejected exception and alerting Slack.
• Handles unmatched payments by writing an exception row to a Google Sheets exceptions sheet and notifying finance in Slack.
• Posts a run-level summary with counts and totals to Slack.

Use cases

• Monthly or daily reconciliation of bank/PSP statements against ERP receivables.
• Reducing manual effort by auto-applying exact invoice matches and using Slack approval for partials.
• Creating an auditable trail of matches, exceptions, and outcomes in Google Sheets.

Technical details

• Integrations: bank/PSP API (HTTP header auth), ERP/accounting API (HTTP request), Slack, Google Sheets.
• Workflow nodes used: if, set, code, wait, slack, switch.

Built for n8n users and automation engineers who need reliable ERP invoice reconciliation with clear human-in-the-loop approvals for partial matches.