WhatsApp transactional messaging API for agencies
Instantly offer WhatsApp services to clients with our WhatsApp transactional messaging API. Just connect an account, add details, and start sending. No lengthy setup or custom infrastructure required.
Official WhatsApp Business Technology partner
Free sandbox environment
Create a WhatsApp sandbox environment for any client in seconds via QR code or connection message. Run up to 50 test messages per day
Ready-made infrastructure
Quickly add new clients with access to hosted API endpoints, webhooks, monitoring, and security, all managed from your MailerSend account.
Dedicated API tokens
Issue separate API tokens per client or integration for clean access management. Create whitelabel dashboards and give clients access.
Spend less time on templates
Pre-approved library
Hit the ground running with 147 multi-lingual, Meta-approved templates covering order confirmations, OTPs, payment reminders, and more.
Sync existing templates
Any templates your clients have already built in Meta are automatically available in MailerSend. No migration work or manual setup needed.
In-app approval and quality tracking
Manage template submissions, track approval statuses, and monitor quality scores for every client without leaving MailerSend.
Give clients custom access
Precise access controls let you invite clients to view their WhatsApp activity, without exposing other clients’ data.
Create API-powered dashboards
Build branded dashboards for each client, powered by our API, and make the impact of your work impossible to miss.
Send any message your clients need
Monitor all activity at a glance
Real-time delivery and read status
Track every message from queued to delivered, with full message details and activity timeline.
Individual client quality ratings
Monitor each client’s quality scores to catch and address issues before they affect deliverability.
Business-level messaging limits
Manage messaging limits for client accounts, and follow Meta's scaling path to increase them over time.
One platform for WhatsApp, email, and SMS
Expand your service offering and earn more from every client, without needing a complex multi-platform setup.
Integrate with Meta Business Suite
View and manage WhatsApp number details for all your clients from within MailerSend, with quick links to manage each account.
Boost engagement with rich media
Go beyond plain text with GIFs, audio, PDFs, and interactive buttons to create messages your clients' customers will engage with.
Grow your WhatsApp service with 24/7 support
New to WhatsApp messaging? Our support team is here 24/7 to help you succeed. Get help for technical issues, use cases, and more.
Scale WhatsApp sending today
MailerSend is a flexible, scalable solution for multi-client businesses. Get all you need to manage multiple clients and onboard new ones fast. Try it today.
FAQs
Why should my clients use transactional WhatsApp?
WhatsApp is the world's most popular instant messaging app. With open rates of 98%, it’s one of the most effective channels for reaching customers with transactional messages.
For agencies that offer transactional email or SMS services, it's a strong upsell opportunity. And with MailerSend’s Business API, you can offer clients access to this high-performing channel without the usual barrier to entry.
MailerSend handles the complex Meta infrastructure so you don't have to build or maintain it, meaning you can onboard clients quickly and start delivering results fast.
Can I test the WhatsApp sandbox on a free plan?
MailerSend’s WhatsApp sandbox is available on the free plan, so you can explore the setup and test functionality before committing to a paid plan or recommending it to clients.
Do I need to verify each client's business with Meta before sending?
Yes. Each client will need to verify their business with Meta to increase message limits and avoid restrictions.
This involves submitting their business details (legal name, address, phone number, website, and a legal document) along with a phone verification. It's worth building this step into your client onboarding process to avoid delays when they're ready to start sending.
Can I use WhatsApp alongside email and SMS?
MailerSend lets you manage transactional WhatsApp, email, and SMS from a single platform using the same API endpoints.
For agencies, this is a significant advantage. You can run multi-channel communications for clients without juggling multiple tools or integrations.
You can also build multichannel fallback workflows to ensure the customer experience is always smooth. If a transactional message on one channel fails, the fallback workflow will trigger a message on another channel.
How do the monthly message allowances and overusage costs work with multiple clients?
Allowances and overuse costs are tied to your plan tier. Higher plans come with larger allowances and lower per-message costs.
If you're managing sending across multiple clients, it's worth factoring in the combined volume when choosing a plan. Visit the MailerSend pricing page for a full breakdown.