Keep one list of every unpaid invoice with its due date. Send a polite reminder by WhatsApp and e-mail before the due date, on the day and after it, and call only the customers who have not replied or who missed a promised date. Write down every promise, so each follow-up starts where the last one stopped.
That is the whole method. The rest of this article shows how to set it up so it runs every week without you.
Why calling every day does not work
Most owners and accountants follow up from memory. Someone remembers a big invoice, makes a call, gets “next week, sir”, and forgets to call back. Small invoices are never chased at all. Then a 45-day bill turns into a 90-day bill.
Daily calling also annoys good customers who were going to pay anyway. And it eats the hours your accounts person should spend on GST returns and bank work.
A fixed routine fixes all three problems. Everyone gets the same polite reminders on the same days. Your calls go only to the few customers who really need one.
Step 1: Make the invoice easy to pay
Many payments are late because something on the invoice is wrong. A customer who claims input tax credit will often hold the payment until a wrong GSTIN, a missing HSN code or the wrong tax type is corrected. Before you chase anyone, check that your invoices carry:
- your GSTIN and the customer’s GSTIN, spelt correctly
- an invoice number that is unique for the financial year
- HSN codes, quantity and taxable value
- CGST + SGST for a sale inside your state, IGST for a sale to another state, and the place of supply
- the amount in words, Indian style (lakh and crore)
- your bank details and a UPI QR code, so the customer can pay the moment they open the PDF
Our GST invoice checklist lists every detail the rules ask for. The rules change from time to time, so check the current list with your CA.
Step 2: Agree the due date in writing
“Payment on delivery” or “the usual” is not a due date. Write the credit period on the purchase order, the quotation and the invoice: “Payment due within 30 days of invoice date”. Then the due date is a fact, not an opinion, and your reminders can quote it.
If your business is a micro or small enterprise registered under Udyam, the law also sets a time limit for your buyers. Read our note on the MSME 45-day payment rule.
Step 3: Fix your reminder days
Pick the days once and use them for every customer. A schedule that works for most manufacturers:
| When | What goes out |
|---|---|
| 3 days before the due date | Friendly note: invoice number, amount, due date |
| On the due date | “Due today” with the bank details |
| 3 days after | Polite reminder: “this is now overdue” |
| 7 days after | Reminder, and a call if there was no reply |
| 15 and 30 days after | Firmer reminder, call from the owner or senior staff |
Send each reminder by WhatsApp and by e-mail. WhatsApp gets read; e-mail leaves a record the customer’s accounts team can forward.
Step 4: Keep the message short and polite
The reminder should carry the facts and nothing else. For example:
Good morning. A reminder that invoice INV/26-27/0412 for Rs 1,18,000 is due on 20 October. Bank and UPI details are on the invoice. Please ignore this if already paid. Thank you.
After the due date:
Good morning. Invoice INV/26-27/0412 for Rs 1,18,000 was due on 20 October and is still open in our books. Could you share the payment date? Thank you.
Never send a reminder for an invoice that is already paid or cancelled. Nothing annoys a customer faster, and it teaches them to ignore your messages. Update your list every day your bank statement comes in.
Step 5: Call only when a call is needed
A call is worth making in four cases:
- The customer has not replied to two reminders.
- A promised payment date has passed.
- The amount is large compared with your monthly sales.
- The customer has paid part, or paid less because of TDS or a dispute, and you need to know why.
Everyone else is handled by the reminders. That is how you stop calling every day.
Step 6: Write down every promise
When a customer says “I will pay on the 25th”, write it against the invoice with the date and the name of the person who said it. Stop the reminders until the 25th. On the 26th, if the money is not in, call and say: “On 18 October you mentioned the 25th. The payment has not come in yet.”
A written history turns a vague chase into a fair, specific conversation. It also means anyone in your team can take over the follow-up when someone is on leave.
Step 7: Look at ageing once a week
Every Monday, look at your outstanding list grouped by age: 0–30, 31–60, 61–90 and 90+ days. Ask three questions:
- Which customers moved into the next bucket this week?
- Which promises fell due and were missed?
- Which large invoices fall due next week?
Fifteen minutes on Monday morning shows you where the money is stuck, before it becomes a 90+ problem. If you want to see what late money is costing you, try our late-payment cost calculator.
Two facts that help you get paid
The 180-day rule for your customer’s input tax credit. Under the second proviso to section 16(2) of the CGST Act, a buyer who has not paid the supplier the value plus tax within 180 days of the invoice date has to pay back the input tax credit claimed, with interest. They can claim it again once they pay. The manner is set out in rule 37 of the CGST Rules. Many accounts teams do not want that reversal, so a polite mention can help with a very old invoice.
The MSME time limit. If you are a micro or small enterprise with Udyam registration, buyers have to pay within the time the MSMED Act, 2006 allows, or pay compound interest at three times the RBI bank rate. You can file a delayed payment case on the MSME Samadhaan portal.
These are summaries for business owners, not legal advice. How they apply to your invoices depends on your facts, so check with your CA.
Checklist
- Every invoice has a correct GSTIN, HSN, tax type, amount in words and UPI QR
- The due date is written on the PO, quotation and invoice
- Reminder days are fixed: 3 days before, on the day, 3, 7, 15 and 30 days after
- Paid and cancelled invoices are removed from the list every day
- Calls only for no reply, a broken promise, a large amount or a short payment
- Every promise is written with a date and a name
- Ageing is reviewed every Monday
Doing this in SmartWorker
SmartWorker reads your invoices and payments from Tally (import from Zoho Books) and sends automatic WhatsApp and e-mail reminders with the amount and due date. Paid or cancelled invoices never get a reminder, a promise to pay by a date pauses reminders until then, and every call, promise and reply is kept in history. Book a free demo to see it with your own invoices.