A digital marketing agency in Jaipur or Dubai that adds WhatsApp to its retainer quickly finds the hard part is not the campaigns. It is keeping a clinic's patient chats, a jeweller's festive offers and a coaching institute's fee reminders apart, while three account executives share the work. WappBlaster gives agencies the official WhatsApp Business Platform to run this on, and this article covers the structure that keeps multi-client work clean: who owns what, how the inbox is divided, and what goes in the monthly report.
Who owns the WhatsApp API account: agency or client
The single most important decision is made before any template is written. The client's Meta Business Manager, its verified business details and its WhatsApp number should belong to the client. The agency is granted admin access. This feels like giving away leverage, but the reverse arrangement creates real trouble: if the relationship ends, the client cannot take its number, its approved templates or its quality history without the agency's cooperation, and any auditor looking at the setup will flag it. WappBlaster's own model works the same way: customers own their Business Manager, and access can be granted or withdrawn by them.
One WhatsApp API number per brand, never a shared agency sender
It is tempting to run small clients through the agency's own number to save setup time. Do not. Recipients see the sender's display name, so a dental clinic's reminder arriving from "Bright Media" is confusing, and blocks earned by one client's careless campaign would lower the quality rating for all of them. Each client needs its own verified number. Meta verification to going live usually takes two to five working days, so build that into onboarding timelines rather than promising a launch next morning.
Dividing the agency's WhatsApp API inbox so nobody answers the wrong customer
When the agency handles replies on a client's behalf, the shared team inbox becomes the working floor. A structure that holds up as the client list grows:
- Assign each client a lead executive and a backup; conversations auto-assign to the lead.
- Tag every conversation with the client and the campaign that triggered it.
- Use internal notes for context the next person needs ("asked for Saturday slot, clinic confirming").
- Agree resolution states with the client: what counts as handled, and what must be escalated to the client's own staff.
- Set a response-time target per client and write it into the contract.
For clients whose staff take over sales conversations themselves, a chatbot can handle first questions and hand the full thread to the client's person, so the agency is not a bottleneck in the middle.
Agency WhatsApp marketing templates, one library per brand voice
A jeweller's Akshaya Tritiya message and a hospital's appointment reminder cannot share wording or tone. Keep templates grouped and named by client ("drsharma_reminder_v2", "kalajewels_festive_hindi"), and use the template manager to see each one's approval status and any rejection reason Meta returns. Rejections are common early on: variables at the start or end of a message, two variables next to each other, or sample values that do not show what the message will really say.
The monthly WhatsApp marketing report agency clients actually read
| Metric | Why the client cares |
|---|---|
| Delivered and read, per campaign | Proof the messages reached people |
| Replied and clicked | Whether the campaign started conversations |
| Opted-out | Early warning that targeting is off |
| Failed, with Meta's reason code | Bad numbers in the client's data |
| Meta charges, itemised | Separates media spend from your fee |
| Quality rating trend | Health of the client's number |
Bill your management fee separately from Meta's per-message charges, which WappBlaster passes through at cost. The platform side is a flat ₹7999 yearly (or $200 for non-Indian businesses) rather than a per-agent charge, so adding a junior executive to the inbox does not change the bill.
WhatsApp API arrangements a marketing agency should refuse
- A client asking you to upload a purchased list "just this once".
- Holding a client's Business Manager under the agency's name.
- Promising reply times your team cannot staff at night or on festivals.
- Reporting only send counts, which invites the question of what the retainer is for.
Agencies that want to resell WhatsApp software under their own brand, rather than manage client accounts, should look at WappBlaster's partner and reseller programme instead, which is a different arrangement from the account management covered here.