Collecting Customer Phone Numbers: Consent, WhatsApp Marketing and the DPDP Act
Published: 10/9/2026
Category: Data & Security
Every shop collects phone numbers at billing. Under India's DPDP law, using them for marketing needs clear consent. How to ask, record and respect consent without slowing down the counter.
Asking "Phone number please?" at billing is routine. Using that number later for festive offers is where many businesses go wrong. Under the DPDP Act, personal data should be used for the purpose people were told about, and marketing generally needs clear, recorded consent. The good news: asking properly takes five seconds at the counter.
Billing purpose vs marketing purpose
| Purpose | What customers expect | What you need |
|---|
| Sending the bill or warranty on WhatsApp | The bill, now | Tell them why you are asking |
| Delivery and order updates | Messages about their order | Same: tied to the order |
| Festive offers and new-arrival messages | Not necessarily | Clear consent, recorded |
How to ask at the counter
Keep it simple and honest:
"Can I take your number for the bill on WhatsApp? And would you also like our offers? You can stop them anytime."
Then record two things: the number, and whether they said yes to offers, with the date.
Other ways to collect consent
- A QR code at the counter that opens a chat saying "Yes, send me offers"
- A checkbox on your online order form (not pre-ticked)
- A reply keyword: "Reply YES to get offers"
Make stopping easy
Every promotional message should include an easy way out ("Reply STOP to stop offers"), and stopping should actually work, the same day. This is good practice under DPDP and also protects your WhatsApp number from being reported.
Do not use numbers from elsewhere
Numbers copied from other groups, bought lists or old visiting cards do not come with consent for your marketing. Using them risks complaints, WhatsApp restrictions and legal trouble.
Keep staff on the same page
- Staff should not save customer numbers on personal phones.
- Customer lists should not be shared in personal WhatsApp groups.
- Exports of customer data should be limited to the owner or a manager.
Where BizFlow fits
BizFlow stores each customer's marketing consent with the date it was given, sends offers only to customers who opted in and removes people who reply STOP. Bills and order updates still go to everyone who shared their number for them. See the WhatsApp CRM.
General information, not legal advice.
Frequently asked questions
Q: Can I send offers to customers who gave their number for a bill?
A: Only if they also agreed to receive offers. Ask clearly at billing and record their answer.
Q: Do I need written consent for WhatsApp marketing?
A: You need clear consent that you can show later. A recorded "yes" at billing, an opt-in message or an unticked checkbox they ticked are practical ways to capture it.
Sources
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