Many clinic owners hear that WhatsApp "now costs money" and assume every message is billed. In practice one rule decides almost everything: the 24-hour window. Once you understand it, you know why one message goes out normally and another needs a template approved by Meta.
This post walks through the rule step by step and applies it to an ordinary clinic day: booking, reminder, prescription and follow-up. There are no price figures here, because prices change and the right place to check them is Meta's official pricing page.
What is the 24-hour window?
When a patient messages your clinic number, a 24-hour window opens. Inside it you can reply with ordinary messages: text, images, PDFs, anything. These are conversation messages.
Every new message from the patient restarts the clock. If a patient writes at 10am and again at 8pm, the window stays open until 8pm the next day.
After the window closes
Once 24 hours pass since the patient's last message, you can no longer send a free-form message. What you can send is a template: pre-written text that Meta has reviewed and approved, with blanks for things like the patient's name and appointment time.
Meta, not your software vendor, charges for these. Templates also have categories (service messages such as reminders and confirmations, versus promotional messages), and the category affects the cost. Check Meta's pricing page before you do any maths.
How this plays out in a clinic day
- Booking and confirmation: the patient started the chat, so your reply is inside the window.
- Reminder 24 hours before the visit: if the patient booked two days ago, the window has closed, so the reminder goes as a template and Meta charges for it. If they were chatting with you shortly before, it may still fall inside the window.
- Sending the prescription after the visit: if the patient wrote to you today, the window is open. If they booked a week ago and have been silent since, you need another route or a template.
- Follow-up after the visit: same rule. It all depends on the patient's last message.
What Kashfy does with this
Kashfy does not charge for reminders. WhatsApp reminders are unlimited on every plan. But a reminder sent more than 24 hours after the patient's last message is a template, and Meta bills you for it on your own number. Kashfy adds nothing on top, but you should know it shows up on your Meta invoice.
There are also cases like a dental treatment plan: WhatsApp only accepts it within 23 hours of the patient's last message, and outside that Kashfy tells you it can't send yet rather than sending something wrong.
All of this runs on your own clinic WhatsApp number on Meta's official Cloud API. There is no shared number.
Ways to cut paid messages sensibly
- Get the patient to reply. A tap on Confirm or Cancel in the reminder, or any reply, opens a fresh window. After that you can send extra details like directions or scan prep as normal messages.
- Put the key info in the confirmation. Address, floor, whether to bring the insurance card. You won't need extra messages later.
- Keep templates short and specific. A plain reminder template is easier to get approved than a long message full of offers.
- Don't mix service and promotion. A reminder is one thing; a laser discount is another, with a different category and cost.
Common mistakes
- Assuming a late reply two days later is free. Once the window closes, you need a template.
- Sending bulk messages to people who never agreed to hear from you. It goes against WhatsApp's rules, can put your number at risk, and annoys patients.
- Counting only how many messages you send. The type and timing matter more.
Where to see your real cost
Open the Meta Business account linked to your clinic number and look at usage and invoices, where messages are split by type. If you are comparing tools, the Kashfy pricing page helps you separate the software cost (per booking) from Meta's cost (per template).
