How to Get the WhatsApp Business API in the UK

Short answer: pick a UK number you own that is not on WhatsApp, sign up through a Meta partner's Embedded Signup (you log in with Facebook, choose or create your business portfolio, add the number and verify it by text or call), and you can start answering customers the same day. Verify your business with Meta using your registered company name to raise your sending limits, and get approved templates before you message anyone who has not written to you first.

Step 1: Which number should a UK business use?

Meta's phone number rules say the number must be yours, must have a country and area code (short codes are not allowed), and must be able to receive a text or a voice call for verification. A UK mobile, a geographic landline or a non-geographic number can all work, with two catches:

• It must not be signed in to WhatsApp. A number already on WhatsApp has to be deleted from it first, which deletes the chat history.
• Landlines and numbers behind a phone menu need care. Meta recommends voice verification for fixed lines, and a number behind an IVR must accept international calls and put the verification call through to a person.

If you want the same number to take phone calls with an AI agent, you can import a number you already hold with Twilio, Telnyx or Plivo for voice. ThinnestAI does not sell UK numbers.

Step 2: How does the sign-up work?

Through a partner, sign-up runs in a Meta window called Embedded Signup. You log in with Facebook, choose or create a business portfolio and WhatsApp account, enter the number, verify it with a code, and set a display name. Meta creates the accounts as you go. On ThinnestAI this happens inside the console, and the number can answer customers once it is verified.

Pick the display name with care. Meta reviews it against its display name guidelines, and a name that does not match your business is a common reason for refusal. If you trade under a name that differs from the company's, make sure your website shows the two together.

Step 3: Verify the business with Meta

New business portfolios start with a limit of 250 people you can message outside a customer service window in a rolling 24 hours, according to Meta's messaging limits page. Completing business verification in Meta Business Suite is one of the two ways to reach 2,000; the other is sending good-quality template messages to 2,000 people within 30 days. Beyond that, limits rise automatically with quality and use.

For a UK limited company, enter the legal name exactly as it is registered and use documents that show that name with your address or phone number. Meta shows the documents it accepts for your country in the verification screen. Verification also lifts the cap on how many numbers you can register from two to twenty.

Step 4: Choose your Meta billing currency carefully

Meta bills its message charges to the payment method on your Meta account. Its pricing page says the currency is chosen when the account is created and cannot simply be changed afterwards; pounds sterling is one of the options. The United Kingdom is its own market on Meta's rate card, so messages to UK numbers have their own rates by category. Our platform fee is separate, billed by card in US dollars; it is on the pricing page.

Step 5: Templates before you start conversations

Replies to a customer who messaged you in the last 24 hours can be free-form. Anything else, such as an appointment reminder or a delivery update, has to use an approved template. Meta says review can take up to 24 hours. Our guide on getting templates approved covers what gets rejected.

What UK rules apply to WhatsApp marketing?

Meta's own rules require opt-in that names your business, and you must respect anyone who asks you to stop. On top of that, UK law on electronic marketing and personal data applies: the Privacy and Electronic Communications Regulations and UK GDPR, overseen by the Information Commissioner's Office. Take advice on how they apply to your messages; you are responsible for meeting them. The product gives you tools such as recorded opt-in, STOP handling and a do-not-contact list you keep. Read WhatsApp's opt-in rules before your first broadcast.

Where is the data kept?

ThinnestAI workspaces outside India are stored in the United Kingdom, in London. Some processing happens outside the UK under transfer safeguards; see where your data is stored.

What you need to start

A UK number you own that is not on WhatsApp, a Facebook login with access to your business portfolio, your registered company details, and a card for Meta's charges. See the UK page and the WhatsApp Business API page.