You've decided your business needs to be on WhatsApp. Smart move. But what number do you actually use? Here's everything you need to know about your options.

If you've read our recent article about why email is dying and WhatsApp is where your customers are, you're probably asking the obvious next question: how do I actually get started?

The first step is simple but crucial: you need a WhatsApp Business number. Without one, you can't create a business profile, you can't send or receive messages, and you certainly can't start building the kind of conversational customer engagement that WhatsApp makes possible.

The good news is you have options. Whether you want to use your existing mobile, repurpose your office landline, or let Meta generate a number for you, there's a route that fits your business. Let's walk through each one.

Understanding the two WhatsApp Business platforms

Before choosing your number, it helps to understand that WhatsApp offers two different business platforms:

WhatsApp Business App is the free app designed for small businesses and sole traders. You can download it from the App Store or Google Play, and it supports up to five devices on a single number. It's straightforward to set up and gives you access to a business profile, quick replies, greeting messages, and a product catalogue.

WhatsApp Business API (also known as the WhatsApp Business Platform) is built for larger businesses that need advanced automation, CRM integration, multi-agent access, and the ability to send messages at scale. The API doesn't have its own interface. Instead, you access it through a Business Solution Provider (BSP) or a platform like Flowella that connects it to your existing tools.

Both platforms require a phone number, and both support mobile numbers, landline numbers, and Meta-generated numbers. The setup process differs slightly depending on which platform you choose.

Option 1: Use a mobile number

This is the simplest and most common route, particularly for small businesses and sole traders.

You can use any mobile number that can receive an SMS or phone call for verification. This includes a dedicated business SIM, a spare personal SIM, or even your existing personal number (though we'd strongly recommend against using your personal number for reasons we'll cover shortly).

How to set it up:

1. Download the WhatsApp Business App from the App Store or Google Play.
2. Open the app and agree to the terms of service.
3. Enter your mobile number when prompted.
4. WhatsApp will send a six-digit verification code via SMS. Enter the code to verify your number.
5. Complete your business profile with your business name, category, description, address, website, and opening hours.
6. You're live and ready to start receiving messages.

Things to keep in mind:

A phone number can only be registered on one WhatsApp application at a time. If your mobile number is already linked to personal WhatsApp, you'll be asked to migrate it to WhatsApp Business. This means you'll lose access to the personal app on that number. Back up your chats before you make the switch.

For this reason, most businesses opt for a separate, dedicated mobile number. A pay-as-you-go SIM card is a low-cost way to get a dedicated business number without tying up your personal line.

Option 2: Use your office landline

This is an underused option that works brilliantly for established businesses. If your customers already know your office phone number, using it for WhatsApp means they can reach you on a familiar number through a new channel.

The setup is almost identical to using a mobile number, with one key difference: landlines can't receive SMS. So when WhatsApp tries to send you a verification code by text, you'll need to let the SMS timer run out and then select the "Call Me" option. WhatsApp will call your landline and read out the six-digit code via an automated voice message.

How to set it up:

1. Download the WhatsApp Business App.
2. When asked for your number, enter your landline number (including the country code).
3. WhatsApp will attempt to send an SMS. Wait for the timer to expire.
4. Select "Call Me" to receive the verification code via voice call.
5. Answer the call on your landline and note down the six-digit code.
6. Enter the code in the app to verify your number.
7. Complete your business profile as normal.

Things to keep in mind:

WhatsApp Business doesn't support phone extensions, so the number needs to ring through to a direct line. If your office phone system uses an IVR (interactive voice response) menu or automated attendant, you may need to temporarily disable it so the verification call comes through cleanly.

Also, remember that once your landline is registered with WhatsApp Business, incoming WhatsApp messages will come through the app, not the phone line itself. Voice calls to the number will still work as normal.

Option 3: Use a Meta-generated number

This is the newest option and one that many businesses don't know about yet. Meta now offers free phone numbers that you can use exclusively for WhatsApp Business. These are sometimes referred to as "555 numbers" because they use a US +1 country code with a 555 area code.

This option is available through the WhatsApp Business API (not the standard Business App) and is typically offered during the embedded sign-up process when you connect through a Business Solution Provider.

Key features of Meta-generated numbers:

They're free to obtain and are automatically verified, so there's no need to receive an SMS or phone call to confirm the number. Your business display name still needs to be approved by Meta before you can start sending messages. These numbers are tied to your WhatsApp Business Account and cannot be transferred to another account or used outside of WhatsApp.

How to get one:

1. You'll need a Meta Business Portfolio (formerly Facebook Business Manager) with your business information completed.
2. Connect to the WhatsApp Business API through a Business Solution Provider or a platform that supports the embedded sign-up flow.
3. During the sign-up process, select the option to "Get a free WhatsApp number provided by Meta" rather than entering your own number.
4. Follow the prompts to create your WhatsApp Business Account and Business Profile.
5. Submit your display name for approval.
6. Once approved, you're ready to go.

Things to keep in mind:

Meta-generated numbers always have a US country code (+1), regardless of where your business is based. For UK businesses, this might look slightly unusual to customers, though in practice most WhatsApp conversations show your business name and profile rather than the raw number.

These numbers also can't be migrated between WhatsApp Business Accounts, so if you need to restructure your Meta setup in the future, you'd need to obtain a new number. They're a great option for getting started quickly, but if having a local UK number matters to your brand, a dedicated mobile or landline may be the better choice.

Option 4: Use a virtual number

Virtual phone numbers are cloud-based numbers that aren't tied to a physical SIM card or phone line. They're managed entirely online and can receive calls and SMS via the internet, making them a flexible option for businesses that want a professional number without additional hardware.

Several UK providers offer virtual numbers that are compatible with WhatsApp Business registration, often starting from around £10 per month. When choosing a provider, make sure they explicitly support WhatsApp Business verification, as not all virtual number providers do.

How to set it up:

1. Sign up with a virtual number provider that supports WhatsApp registration.
2. Choose your preferred area code and number.
3. Configure call routing so you can receive the verification call or SMS.
4. Register the virtual number in the WhatsApp Business App or through the API, following the same verification steps as above.

Things to keep in mind:

Meta has restrictions on some VoIP numbers, particularly US-based ones. Not every virtual number provider will work. Always confirm WhatsApp compatibility before committing to a provider. Also make sure you keep the virtual number active, as you may need it for re-verification in the future.

Which option is right for your business?

The best choice depends on your size, your goals, and how you want customers to perceive your business.

If you're a sole trader or small business just getting started with WhatsApp, a dedicated mobile SIM is the quickest and cheapest route. Download the app, verify your number, and you can be live within minutes.

If you're an established business with a well-known office number, using your landline lets you leverage existing brand recognition. Customers who already know your phone number can now reach you on WhatsApp without needing to learn a new number.

If you want to get started with the WhatsApp Business API quickly and don't mind a US-format number, a Meta-generated number removes the need for any phone hardware entirely. It's free, it's instant, and it's already verified.

If you need maximum flexibility and a professional setup, a virtual number gives you a dedicated business line with cloud-based management, local area codes, and no physical SIM required.

Getting your number is just the beginning

Having a WhatsApp Business number is the foundation, but the real value comes from what you do with it. Most businesses set up their number, create a profile, and then... wait. They treat WhatsApp like a phone line, sitting there hoping customers will message them.

The businesses seeing real results are the ones proactively engaging customers on WhatsApp from the moment they show interest, and that's where Flowella comes in.

Flowella connects your existing forms to WhatsApp, transforming static form submissions into dynamic WhatsApp Flows. When a potential customer fills out a form on your website, instead of receiving a generic email confirmation, they're immediately engaged in an interactive WhatsApp conversation that qualifies their interest, answers their questions, and moves them towards a decision.

And because Flowella integrates directly with HubSpot, every conversation is tracked, every contact is updated, and every interaction enriches your CRM with the data your team needs.

Whether you've just set up your WhatsApp Business number for the first time or you've had one for a while but aren't seeing the engagement you expected, Flowella bridges the gap between having a number and actually using it to grow your business.

Ready to turn your WhatsApp Business number into a lead generation engine? Visit flowella.io to see how it works.

Flowella converts your existing forms into interactive WhatsApp Flows, with direct HubSpot integration. Learn more at flowella.io