Invoice & Payment Tracker Template — Which Invoices Are Late and How Late Are They, Answered Before You Ask

Most invoice tracking starts the same way: someone opens a spreadsheet, scans dates, does mental math, and fires off a follow-up email. By the time anyone notices an invoice is 45 days overdue, the conversation is already awkward and the cash flow damage is done.

The OpenSource AI Pro Invoice & Payment Tracker replaces that manual scan with a formula-driven system that flags overdue invoices the instant they cross their due date, notifies the right person exactly once, and delivers a daily digest of everything outstanding. You never chase — the template chases for you. Self-hosted on Baserow, zero per-seat fees, unlimited users.

Key Features

• Automatic Overdue Detection — A formula flag marks every invoice as overdue the moment today's date passes the due date. No manual check, no missed deadlines. The flag is always current because the formula recalculates live.

• Outstanding Balance Rollup — Every client record rolls up unpaid invoice totals automatically. Open any client and see exactly how much they owe across all invoices, without building a pivot table or running a report.

• Exactly-Once Overdue Alerts — When an invoice flips to overdue, an event-triggered email fires to the assigned account owner. A _notified_overdue stamp ensures the alert sends once and only once — no duplicate emails, no alert fatigue. The stamp re-arms automatically when the invoice is paid and a new one goes overdue.

• Daily Overdue Digest — A scheduled automation sends a morning summary of all currently overdue invoices, grouped by client, with amounts and days-past-due. Finance leads start the day knowing exactly where to apply pressure.

• Aging Buckets at a Glance — Formula-driven aging categories (Current, 1-30, 31-60, 61-90, 90+) let you filter and sort without any manual classification. The buckets update themselves as time passes.

• Payment Status Workflow — Track invoices from Draft through Sent, Partial, Paid, and Written Off. Each status change is timestamped, giving you a clean audit trail.

How It Works

The system runs on three layers that work together without any code:

Formula Flags. The Is_Overdue field is a Baserow formula that compares the invoice due date against today. If the due date has passed and the status is not "Paid," the flag flips to true. The Days_Overdue field calculates exactly how many days late each invoice is. The Aging_Bucket field categorizes the overdue period automatically.

Event-Triggered Alerts. A Baserow automation watches for the overdue flag. When an invoice transitions from not-overdue to overdue, the automation sends an email to the linked account owner. The _notified_overdue timestamp field acts as a stamp — the automation checks whether the stamp exists before sending, so the same invoice never triggers two alerts. When the invoice is eventually paid, the stamp clears, ready for the next cycle.

Scheduled Digest. A second automation runs on a daily schedule. It queries all invoices where Is_Overdue is true, formats them into a summary with client name, invoice number, amount, and days overdue, and emails it to the finance team. One email, every morning, covering everything that needs follow-up.

Who It's For

• Freelancers and consultants tracking 10-100 invoices per month who cannot afford to let payments slip through the cracks
• Small business finance teams managing receivables across multiple clients without dedicated AR software
• Agencies billing retainer and project-based clients on different schedules who need a single source of truth
• Bookkeepers and accountants supporting multiple small businesses who want one system per client without per-seat SaaS costs
• Operations managers in service businesses where cash flow depends on timely invoice follow-up

vs the Alternatives

| Feature | OpenSource AI Pro | Airtable | Monday.com | Notion | |---|---|---|---|---| | Auto overdue flags | Formula-driven, live | Manual or paid extension | Requires automation recipes (limited on free) | No native formula flags | | Email alerts on overdue | Built-in, exactly-once | Requires paid automations | Per-seat pricing + automation limits | No native email triggers | | Daily digest email | Included | Paid automation tier | Paid tier | Not available | | Per-seat pricing | Zero — unlimited users | $20+/seat/month | $10+/seat/month | $10+/seat/month | | Self-hosted option | Yes, on Baserow | No | No | No |

What's Included

Tables:

• Invoices — invoice number, client link, amount, due date, status, payment date, notes
• Clients — company name, contact, email, Outstanding_Balance rollup
• Payments — payment date, amount, method, linked invoice

Key Formula Fields:

• Is_Overdue — boolean flag comparing due date to today
• Days_Overdue — integer count of days past due
• Aging_Bucket — categorical label (Current, 1-30, 31-60, 61-90, 90+)
• Outstanding_Balance — rollup sum of unpaid invoices per client

Automations (2):

1. Event-triggered overdue alert with _notified_overdue stamp
2. Scheduled daily overdue digest email

Views:

• All Invoices (grid)
• Overdue Invoices (filtered)
• By Client (grouped)
• Aging Summary (grouped by bucket)

Get Started Free

Download the Invoice & Payment Tracker template and import it into your self-hosted Baserow instance. No account required, no credit card, no per-seat fees. Your data stays on your server.

Download Free Template

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