Messaging API
Engage your customers with our Voice API
With customer contact and sales teams often under pressure, our Interactive Voice Responses (IVR) and Interactive Voice Messaging (IVM) are designed to free up agents – reducing the cost-to-serve and improving customer satisfaction. Our Voice API encourages customers to self-serve, or amplify your marketing messages.
Scalable and secure, our powerful Voice API connects to your business systems in just a few hours and can be accessed by office-based, remote and field staff. Both developers and no-code teams will find set-up straightforward – and you should be up and running in just a few hours.
The Esendex multi-channel API is build-once, so users benefit from continuous support, regular updates and new features that improve usability and performance.
Everything you need from a Voice API
Fast set-up
Deploy at speed whether your agents are in a contact centre or remote.
Security as standard
Esendex is ISO 27001 accredited – helping you safeguard customers’ data and stay GDPR compliant.
Fully customisable
Allow your customers to steer conversations when and how they want with our customisable IVR and IVM systems.
>5bn messages
Each year over five billion messages are delivered through our messaging API by businesses worldwide.
99.9% uptime
Scale your messaging without experiencing dips in performance. Rely on 99.9% uptime for reliability during peak times.
<2 hours
Most teams send their first live message in under two hours with our straightforward set up, integration and expert support.
Built by developers, for developers. Integrate our email API for simple, real-time communication
Use our API documentation to integrate Esendex’ services into your systems within minutes. Here’s how to send an email:
// The POST v1/messages endpoint allows you to send a message to a single contact in one request.
// The message can also be sent via different channels; including SMS, Whatsapp and RCS.
curl -X POST 'https://api.esendex.co.uk/v2/messages' -H 'X-Api-Key: {{your-key-here}}' -H 'Content-Type: application/json' -d
{
"accountReference": "EXxxxxxxxx",
"name": "name",
"characterSet": "characterSet",
"channel": "channel",
"from": "from",
"validity": "2025-07-30T09:38:04.4517739+00:00",
"messageType": "messageType",
"body": {
"text": "text",
"templateId": "templateId"
},
"recipients": [
{
"msisdn": "msisdn",
"variables": {},
"metaData": {}
}
],
"addressBook": {
"contacts": [
{
"id": "id"
}
]
},
"metaData": {}
}No commitment, 30 day free trial
Begin your journey by opening a free Esendex account today and get 100 SMS credits.
Ready? Set? Go!
Learn how to get your service up and running with our simple quickstart guides.
Not a coder? We’ve got you covered
Our managed services team can help you set up and run your email API at no extra cost. From initial configuration to testing and live deployment, we’ll make sure everything is in place so you can start sending messages with confidence.
“Operationally, WhatsApp offers significant engagement opportunities – from outbound notifications, reminders and status updates to marketing and promotions. The combination of chatbot automation and WhatsApp has also had a direct impact on our bottom line”
Lucie Riley – Chief Operating Officer, Rhenus Home Delivery
Let’s start sending, together.
Discover the full power of our mobile messaging platform.
Why choose Esendex?
Having us in your corner ensures that you can support your customers and your business – whatever comes your way.
20+ years of experience
Industry leading support
An expert and reliable partner
One-on-one with everyone
Flexible and scalable options
Solutions designed for you
Get the most out of Voice with our flexible API
Increase efficiency
Pre-qualify customers by asking them to confirm their details before transferring them to an agent.
Strategic automation
With light touch and ethical data capture, our automated service allows self-serve, or be transferred when live agent support is required.
Voice broadcasting
Pre-recorded voice messages options to create, schedule and send mass calls and voicemails in bulk.
Easily connect to industry-standard applications
Integrate with industry-standard contact centre and marketing software.
Scalable
Manage peaks in demand – delivering positive customer experiences, without increasing headcount and costs
Sender ID
Build trust with Sender ID to demonstrate that the call comes from a legitimate organisation.
FAQs
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Is your Voice API secure?
Is your Voice API secure?Esendex is ISO 27001 accredited and supports compliance with GDPR – so you can safeguard personal information and payment data, no matter where your teams are based.
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( Missing number ) How many applications integrate with Voice API?
We offer [insert number] integrations, which allow users to easily manage conversations – from automated reminders to two-way customer service messaging.
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What kind of support is available during and after integration?
You’ll have access to 24/7 support from our expert team, plus free setup assistance if you need it.
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What programming languages are supported?
JavaScript, Python, Java, C#, PHP and cURL are all supported, enabling fast integration.
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Is there a sandbox or testing environment available?
Yes. You can test and simulate messages safely using our dedicated sandbox environment.
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Do I need coding skills to use the API?
No. While developers can integrate directly, no-code teams can use our tools and guided setup.
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Is it customisable?
Yes. You can define and customise menus based on voice or by asking the customer to press the keypad (Dual-Tone Multi-Frequency – DTMF).
