Which number to use for WhatsApp
Sonar sends and receives from a WhatsApp number in your business's name. If you don't have a spare one, here's how to get one today, and the two rules that decide whether a number will work.
The two rules
- It has to get a code once. When you connect, Meta sends a 6-digit code to the number by SMS or reads it out in a phone call. Any number that can receive one of those works: a cellphone, a landline or an office line. A short code or a number behind a "press 1" menu won't.
- It can't still be on ordinary WhatsApp. A number is on either personal WhatsApp or WhatsApp for business, not both. The one exception is the WhatsApp Business app: you can keep using the app and connect the same number to Sonar.
Your options
| Number | Good for | What to know |
|---|---|---|
| A new prepaid SIM | Most businesses. Cheap, quick, and only used for WhatsApp. | A starter pack from MTN, Vodacom, Telkom or Cell C, RICA'd in the shop. It only needs to be in a phone to get the code. |
| Your landline or office number | The number customers already know. | Choose a phone call for the code, and make sure a person answers it rather than a menu. |
| Your WhatsApp Business app number | Keeping your chats and carrying on in the app. | Connect it with "Your WhatsApp Business app number". See Sonar with the WhatsApp Business app. |
| A number on personal WhatsApp | A cellphone that's really the business's number. | Move it to the WhatsApp Business app first, or delete the WhatsApp account on it. How. |
A prepaid SIM, step by step
- Buy a starter pack from any network at a supermarket or phone shop. They cost very little.
- RICA it at the counter. By law you need your ID and a proof of address. For a business number, register it to the person who looks after the business's WhatsApp.
- Put it in any phone and note the number. It doesn't need WhatsApp installed.
- In Sonar, go to WhatsApp numbers → + Add a number → A number that isn't on WhatsApp and press Start. Sign in with Facebook, add the number, and choose Text message for the code.
- Type in the code from the SMS. Once Sonar says it's connected, the SIM can come out of the phone. Keep it somewhere safe.
A landline or office number
Follow the same steps, but choose Phone call for the code. Meta calls the number and reads the code out, so someone needs to be at that phone with a pen when you press it. A number that goes through a switchboard or a "press 1 for sales" menu won't reach a person in time, so use a direct line.
Your customers can then WhatsApp the same number they already call. Calls still ring your landline as normal.
A number on personal WhatsApp
If the number is on ordinary WhatsApp on someone's phone, pick one of these first:
- Keep the chats: install the free WhatsApp Business app on that phone and move the number into it (the app offers this when it starts). Then connect it to Sonar as "Your WhatsApp Business app number". The chats stay, and the app keeps working.
- Start fresh: in WhatsApp, delete the account on that number under Settings → Account → Delete my account. This removes the chats from WhatsApp on that phone. Then connect it as a new number.
If the phone belongs to someone personally, a separate SIM for the business is usually simpler.
Keep the number
- Keep a prepaid SIM active. Networks switch off prepaid numbers that go unused for a while, and can give them to someone else. Keep a little airtime on it and use it now and then, for example a short call or SMS every month or two.
- Why it matters: Meta can ask for a new code, for example if the number is ever moved or set up again. Without the SIM, you can't get it.
- Use a business number, not a person's. If someone leaves, the business keeps its WhatsApp number and every chat in Sonar.
Get a one-time number from Sonar
You can get a one-time South African mobile number from Sonar when you add a number: R119 once, with no monthly fee. No SIM or phone is needed, because Sonar receives Meta's code and shows it to you.
It takes one code, once, so connect it within 20 minutes of getting it. After that it can't receive another code, calls or SMS, and it can't move to another provider. If WhatsApp ever asks to verify the number again, it can't be recovered, so for a number you'll want for years, a prepaid SIM in your business's name is the safer choice.
More guides
- WhatsApp pricing in South Africa
- POPIA and WhatsApp marketing
- Event invites with one-tap RSVPs
- AI Agent and Copilot: a WhatsApp chatbot in your voice
- Use Sonar with the WhatsApp Business app
- Import your contacts
- Order and booking updates from your other systems
- Connect a client's WhatsApp number
- WhatsApp API providers in South Africa, compared
- Developers: API and webhooks
- Switching to Sonar
- WhatsApp RSVPs for events
- Competitions and prize draws
Need a hand?
Email support@whats-hub.co.za and we'll help you choose a number and connect it.