n8n Till Cash Leak Monitor: Google Sheets, Gmail & Telegram

Detect cash leaks in your till closeouts—automatically reconcile, validate, and alert overnight

n8n Till Cash Leak Monitor nightly reconciles your till closeout submissions, finds cash variances outside a tolerance band, flags missing or malformed rows, quarantines duplicates, and escalates repeat offenders via Gmail and Telegram. It also produces a daily digest in Google Sheets (optionally narrated with OpenAI) so you always know what happened.

What this workflow does

• Runs nightly (or via manual Test workflow) to collect today’s till submissions and fetch the prior 30 days of till history.
• Validates each row, separating complete entries from malformed ones, and determines “today” based on the latest date in the batch.
• Scores 30-day history to calculate cumulative leak totals and count prior over-band shifts per staff member.
• Detects operational issues by flagging missing required fields, identifying date+shift duplicates, and inferring submission gaps between the last historical date and today.
• Compares cash vs expected sales per unique shift against a tolerance band (the max of a flat amount or a percent of sales), labeling results as clean, alert-worthy, or escalation-worthy.
• Routes outcomes: writes clean results back to the till log, quarantines duplicates/malformed rows in a quarantine sheet, sends first-offense and gap alerts by Gmail, escalations by Telegram, and one per-run digest by Telegram (optionally narrated with OpenAI).

Use cases

• Keep till audits consistent by automatically catching missing submissions and malformed rows.
• Reduce fraud risk by detecting cash variances and escalating repeat offenders.
• Prevent duplicate closeout reporting with date+shift duplicate detection and quarantine.

Technical details

• Google Sheets for till logs, quarantines, and daily digests.
• Gmail for first-offense and gap alerts.
• Telegram for repeat-offender escalations and per-run digests.
• n8n nodes/workflow components include: if, code, gmail, merge, open ai, switch.