Customers read WhatsApp messages sooner than email. That is why more businesses connect their software to it, so that invoices, reminders and updates go out without anyone typing them. This guide explains how the WhatsApp Business API works and what to plan before integrating it.
Who wrote this guide
The EZ Solutions team wrote this guide. Our system integration team connects WhatsApp to business software, and products such as BillDo and ServicePilot share bills, reminders and service updates on WhatsApp.
What is the WhatsApp Business API?
The The API is the interface that lets software send and receive WhatsApp messages. It is different from the WhatsApp Business app, which one person runs by hand on a phone. The API serves teams and systems: many agents, automatic messages and links to other software.
How does the integration work?
The business registers a number and connects through an approved provider. Software then sends a message through the provider, and the provider calls a webhook, a web address in the software, whenever a customer replies or a message is delivered. The software can store replies against the right customer record.
What are templates?
A business can start a conversation only with a pre-approved template, for example an invoice notice, a payment reminder or an appointment confirmation. Once the customer replies, a session opens and free-form replies are allowed for a limited time. Template wording is reviewed, so it should be clear and specific.
What is opt-in?
Customers must agree to receive messages. Common ways to collect opt-in are a tick box on a form, a first message from the customer, or consent captured at sign-up. Keep a record of when and how consent was given.
What can be sent?
- Invoices and payment reminders with payment details.
- Order, delivery and service-visit updates.
- Booking confirmations and check-in instructions.
- Replies from a WhatsApp chatbot.
What should be planned first?
- The messages that matter most, and the template for each.
- Where customer phone numbers and consent are stored.
- Who answers replies, and how a chat is handed to a person.
- Reliability: retries, alerts and a log of what was sent, as described in API integration.
What mistakes delay approval and delivery?
Template rejections are the most common delay. Vague wording, promotional language in a utility message and missing variables all cause rejections. Delivery problems come from wrong phone formats, missing consent and a number that was registered on another service. A checklist before submission saves days.
How should costs be planned?
Providers and the platform charge by conversation type or message, plus any monthly fee of the provider. Estimate the monthly volume of each message type, such as invoices, reminders and updates, and check the current pricing of the chosen provider before committing.
Who should own the messages?
A named person should own the templates, the opt-in records and the replies. When the business changes a process, the matching template changes too. Without an owner, wording becomes outdated and customers receive messages that no longer match what happens.
How is delivery monitored?
Track messages sent, delivered, read and failed, with the reason for each failure. Alerts for sudden drops in delivery, such as a template paused by the platform, let the team react before customers notice. Logs also help answer the question of whether a customer received a specific message.
What about privacy?
Messages often carry names, amounts and addresses. Send only what the message needs, protect the access keys and limit who can read the conversations. Honour opt-out requests promptly and keep a record of consent, so the business can show how each number was added.
How EZ Solutions integrates WhatsApp
The team maps the messages, registers the templates with the provider, connects the webhook and tests delivery end to end. The messages then appear inside the business software, not in a separate inbox.
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