Automate Invoice Follow-Ups With Hermes Agent: Google Sheets vs Apple Numbers

The cost of manual follow-ups

Canadian SMBs wait an average of 12 days past due for invoice payment. Roughly 20% of invoices are never paid without follow-up. But the follow-up itself is uncomfortable — nobody wants to be the person sending "just checking in" emails. So invoices sit. Cash flow tightens. And the awkwardness grows with each passing day.

Hermes Agent removes the emotion from the equation. It sends polite, consistent reminders on a schedule. If a client gets annoyed, they're annoyed at the automated system — not at you. Meanwhile, your cash flow improves by 30–50%.

Approach 1: With Google Sheets + Gmail

This is the most automated path. Your invoice tracker lives in Google Sheets. Hermes reads it, drafts emails, and updates statuses — all via API. You review drafts on your phone and approve with one tap.

What you need

• A Google Sheets invoice tracker (template below)
• Google Workspace connected to Hermes Agent
• A messaging platform (Telegram or WhatsApp) for draft approvals on the go

Your invoice tracker template

Create a Google Sheet with these columns:

Statuses: Draft → Sent → Stage 1 (Day 7) → Stage 2 (Day 14) → Stage 3 (Day 30) → Escalated → Paid. Hermes moves each invoice through the stages automatically.

Step-by-step setup (35 minutes)

1. Create your tracker sheet with the columns above. Add your outstanding invoices.
2. Connect Google Workspace if not already done: hermes setup google-workspace.
3. Create the invoicing skill. Tell Hermes: "Each weekday at 9 AM, read my invoice tracker sheet. For every invoice where Status ≠ Paid: if today is 1 day after Date Sent and Stage=1, draft a 'thanks for your business, invoice attached' confirmation. If today is 7 days after Date Sent and Stage=1, draft a friendly reminder. If today is 14 days after Date Sent and Stage=2, draft a firmer follow-up. If today is 30 days after Date Sent and Stage=3, draft an escalation notice and flag for my personal attention. Update Last Follow-up and advance the Stage after each action. When Status is set to Paid, stop all follow-ups for that invoice."
4. Schedule as a cron job — weekdays at 9 AM.
5. Review drafts on your phone. Hermes delivers: "3 reminders ready: Acme Corp (Stage 1, $2,400), Beta Ltd (Stage 2, $850), Gamma Inc (Stage 3 — YOUR REVIEW NEEDED). Reply 'send all' or review individually."

Approach 2: With Apple Numbers + Apple Mail

Apple Numbers doesn't have a public API, but Hermes can read and interact with Numbers files via macOS automation — the same way it controls Mail.app. Your invoice data stays on your Mac, and reminders go out through Apple Mail or your messaging gateway.

What you need

• A Mac running macOS 14+
• Your invoice tracker in Apple Numbers (same columns as the template above)
• Hermes Agent with computer-use enabled
• Apple Mail configured for sending reminders

Step-by-step setup (50 minutes)

1. Create your Numbers tracker with the same columns: Client, Invoice #, Amount, Date Sent, Due Date, Status, Last Follow-up, Stage. Keep it in a consistent location (e.g., ~/Documents/Invoicing/Invoice Tracker.numbers).
2. Create the Numbers-reading skill. Tell Hermes: "Each weekday at 9 AM, open the Numbers file at ~/Documents/Invoicing/Invoice Tracker.numbers. Read the invoice table. For every row where Status ≠ Paid: calculate days since Date Sent. If day 1, prepare a confirmation email. If day 7 and Stage=1, prepare a friendly reminder. If day 14 and Stage=2, prepare a firmer follow-up. If day 30 and Stage=3, prepare escalation. Show me all drafts for approval. After I approve, update the Last Follow-up date and Stage in Numbers."
3. Use Apple Mail for sending. Hermes opens Mail.app compose windows, fills in the recipient and body from your Numbers data, and saves drafts. You review and send.
4. Schedule as a daily cron job at 9 AM, weekdays only.

What happens behind the scenes

Hermes opens Numbers, reads the cell values from your tracker table, calculates which invoices need action, drafts emails in Apple Mail, then updates the Numbers file with new dates and stages. Everything happens locally on your Mac. Only the AI processing (determining which stage each invoice is in, drafting polite reminder text) goes to your model provider.

Google Sheets vs Apple Numbers: which should you choose?

Beyond reminders: building a complete AR workflow

• Payment detection. If you use online payments (Stripe, Square), Hermes can check for new payments and auto-update your tracker to "Paid."
• Client-specific tone. Hermes remembers that Acme Corp prefers formal language while Beta Ltd responds better to casual check-ins. Persistent memory handles this automatically.
• Weekly AR report. "This week: 8 invoices sent ($18,400), 5 paid ($11,200), 3 reminders sent. Average days to payment: 7. Oldest overdue: 28 days (Gamma Inc, $4,200)."
• Deposit tracking. For clients who pay 50% upfront, Hermes tracks both payments and adjusts reminder timing accordingly.

Frequently asked questions

Will clients know the reminders are automated?

Not if you don't want them to. Hermes matches your tone and signs emails with your name. The reminders feel personal because they reference the actual project and amount. Most clients won't know — and many won't care as long as the reminder is polite and timely.

What if a client disputes an invoice?

If a client replies with a dispute ("this amount is wrong," "we already paid"), Hermes flags it immediately and stops all future reminders for that invoice. The reply lands in your inbox with a "Dispute — needs your attention" label. Hermes never argues with clients.

Can Hermes handle multiple currencies and tax rates?

Yes. Add a Currency column to your tracker and Hermes will include the correct symbol in reminders. For Canadian businesses dealing with GST/HST, add a Tax column — Hermes can reference the tax breakdown if a client questions the total.

Is this legal in Canada? What about collection laws?

Automated reminders are standard business practice and fully legal. Hermes never threatens, never misrepresents, and always identifies itself as coming from your business. If an invoice reaches the escalation stage, Hermes drafts a notice but requires your explicit approval before sending. This keeps you compliant with provincial collection practices legislation.

Related guides

• Top 5 SMB Automations with Hermes Agent
• Automate Email Follow-Ups
• Email and Admin Automation for Canadian SMBs
• Hermes Agent with Google Workspace