💬WhatsApp

Quickly connect to WhatsApp Cloud API through Meta embedded signup, and complete the correct setup based on your existing account, phone number, and use case.

FIRST LINE is expected to provide a new one in 2026 Q3 embedded registration connection method. You can start directly from FIRST LINE and follow the Meta screens to complete authorization for the account and phone number. There is no need to prepare separate developer settings, and no need to set up Webhook or Verify Token yourself.

If you are already using the WhatsApp Cloud API in FIRST LINE, please first refer to “If you are already using the FIRST LINE WhatsApp Cloud API, how do I upgrade?” below. When upgrading, please keep the original Business Portfolio, and make it your main goal to continue using or transfer the original phone number. The original official WhatsApp account may not appear in the embedded registration screen.

First confirm which situation you are in

Before you begin, first confirm how the current WhatsApp phone number is being used. Different situations require different follow-up steps.

Current situation	Recommended approach
Using WhatsApp Business Platform for the first time	Complete the setup according to “Connect WhatsApp for the first time” on this page.
Already using the WhatsApp Cloud API in FIRST LINE	Keep the original Business Portfolio and complete embedded registration with the original phone number. The original official WhatsApp account may not appear; if necessary, you can create a new official WhatsApp account according to the Meta screen as the transfer destination.
The phone number is currently being used in the WhatsApp Business App	First confirm whether you still need to keep using the WhatsApp Business App. Do not delete the account or phone number in the app before starting the connection, and follow the connection method shown on the Meta screen.
The phone number is currently managed by another provider	A number transfer is usually required. Please keep the original account and phone number, and first confirm that you still have admin access to that Meta Business Portfolio and WhatsApp phone number, then follow the Migration / Transfer process shown on the Meta screen.

If you already have a WhatsApp phone number in use but are not sure which situation it belongs to, first check in Meta Business Suite / WhatsApp Manager which official WhatsApp account the phone number currently belongs to, and whether it is still shown in the original service. After confirming, choose the process according to the table above. Do not delete the original Business Portfolio, official WhatsApp account, or phone number first.

Prepare before connecting

Before starting, it is recommended to confirm the following first:

• You have an account that can log in to Meta / Facebook.

• That account has admin access to the company’s Meta Business Portfolio.

• If the company already has an official WhatsApp account or phone number, log in with the Meta account that has permission to manage those assets.

• It is recommended to keep the Meta business profile complete, including the company name and a publicly accessible business website, to avoid affecting later review or account setup.

• If you want to use your own phone number, make sure the number can currently receive SMS or voice calls so that you can complete Meta’s verification.

• If the company already has a WhatsApp phone number, first confirm whether it is currently managed by FIRST LINE, the WhatsApp Business App, or another provider.

• If the existing phone number has WhatsApp two-step verification enabled, make sure you know the currently set 6-digit PIN. Some existing numbers still need this PIN after authorization is completed in order to finish phone number registration.

If you are not sure about the relationship between the Business Portfolio, official WhatsApp account, and phone number, you can first go to Meta Business Suite → Settings → WhatsApp Accounts / WhatsApp Manager to check the current official WhatsApp account and phone number before starting the FIRST LINE authorization process.

Connect WhatsApp for the first time

Step 1: Open WhatsApp authorization from FIRST LINE

Go to the channel settings page in FIRST LINE, find the WhatsApp item, then click the Connect / Add button.

Step 2: Start Meta authorization

After clicking the Meta authorization button on the FIRST LINE screen, the system will open the Meta settings window.

Please log in with the Meta account used to manage the company’s official WhatsApp account, and click Continue.

Step 3: Select a Business Portfolio

Select the actual Meta Business Portfolio.

used by the company. If the company already has WhatsApp Cloud API, be sure to select the original Business Portfolio and do not create a new one just to complete the process.

Step 4: Select or create an official WhatsApp account

Then follow the Meta screen instructions:

• There is an available official WhatsApp account on the screen: select the account suitable for this connection.

• The original official WhatsApp account does not appear: this does not necessarily mean something was done wrong. If it is still under the original Business Portfolio, you can create a new official WhatsApp account according to the Meta screen to serve as the transfer destination for the original phone number.

• Using it for the first time: create a new official WhatsApp account according to the screen.

For existing FIRST LINE WhatsApp Cloud API users, the key is to keep the original Business Portfolio and continue using or transfer the original phone number. There is no need to assume you must select the original official WhatsApp account.

Step 5: Set the WhatsApp phone number

Choose according to your use case:

• Use an existing phone number: if the company already has a WhatsApp Cloud API phone number in use, complete the connection or transfer with the original phone number.

• Add a phone number: follow the Meta screen to complete phone number setup and verification. When using your own phone number, you usually need to complete verification via SMS or voice call.

• Display name only (Use a display name only): if this option is provided on the Meta screen, you can use the number provided by Meta to complete the setup. The actual available scope and eligibility depend on the settings currently provided by Meta; if you are preparing for official external service, it is still recommended to use a phone number actually managed by the business.

Step 6: Confirm and complete authorization

After confirming that the Business Portfolio, official WhatsApp account, and phone number on the screen are correct, follow Meta’s instructions to complete authorization.

After completion, please return to FIRST LINE.

Step 7: Return to FIRST LINE to continue setup

After completing Meta authorization, please return to FIRST LINE. Once the authorization window is finished, FIRST LINE will refresh the current WhatsApp account and phone number information.

The overall process can be understood as:

Meta authorization complete → return to FIRST LINE → register the phone number if needed → confirm the connection → test sending and receiving

If the Meta screen shows “Complete,” it means the authorization step on the Meta side is finished, but it does not mean FIRST LINE has completed all subsequent settings. Please return to FIRST LINE to continue confirming the phone number and connection status.

Step 8: If the screen provides a phone number registration entry, enter the 6-digit PIN

For accounts authorized through embedded registration and that have obtained phone number information, FIRST LINE may show the phone number registration entry.

At present, this entry means you can perform Meta’s phone number registration process from FIRST LINE; it does not mean FIRST LINE has accurately determined that the Meta side is definitely still in an “unregistered” state.

If you need to complete phone number registration, please enter the current WhatsApp two-step verification 6-digit PIN, then submit according to the screen.

This 6-digit PIN is the WhatsApp two-step verification PIN, not the Meta / Facebook login password, and not the one-time verification code received via SMS or voice call.

If you do not know the current 6-digit PIN:

1. First go to WhatsApp Manager to find this phone number.

2. Check the two-step verification settings for that phone number.

3. Reset or update the PIN according to the method provided by Meta.

4. After that, return to FIRST LINE and perform phone number registration.

Step 9: Confirm the connection and test sending and receiving messages

After completing the required settings, first confirm that FIRST LINE can obtain the expected WhatsApp account and phone number, then perform an actual send/receive test:

1. Use another WhatsApp account to send a message to the company’s WhatsApp number.

2. Confirm that FIRST LINE can receive the message.

3. Reply from FIRST LINE and confirm that the other side can receive it normally.

After confirming that both receiving and sending work properly, begin using it officially.

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How do I upgrade a Cloud API originally created in Meta Developer Portal?

Some earlier WhatsApp Cloud API users first Meta Developer Portal created an app there, then added the phone number to the official WhatsApp account used by that app. When switching this type of existing phone number to the new embedded registration, it may not appear directly in the list of available or transferable numbers.

If embedded registration cannot directly continue using the original number, and you still have admin privileges for the Meta Business Portfoliothat originally bound this phone number, you can first remove the phone number from the original official WhatsApp account, release the number, and then reconnect through FIRST LINE’s embedded registration.

This process will remove the phone number from the original official WhatsApp account. Please first confirm that you really want to transfer that number to the new process, and keep the original FIRST LINE Channel and related settings. Do not delete the existing FIRST LINE channel at the same time.

Steps to handle it

1. Log in Meta Business Settings, and switch to the Business Portfolio that originally managed that WhatsApp phone number.

2. Go to “Accounts” → “WhatsApp Accounts”.

3. find the original official WhatsApp account being used, and open WhatsApp Manager.

4. In WhatsApp Manager, enter from the left side “Phone Numbers”.

5. find the phone number to transfer, and confirm that you currently have admin access.

6. If that phone number has enabled WhatsApp two-step verification (2FA), first follow the Meta screen to turn off two-step verification or complete the necessary disablement setup.

7. Click the delete / trash bin operation next to that phone number, and follow the Meta screen to enter your Facebook / Meta account password to confirm.

8. After confirming that the phone number has been removed from the original official WhatsApp account, return to FIRST LINE.

9. Start again from FIRST LINE embedded registration, select the original Business Portfolio, and re-add or register the phone number that has just been released.

10. After authorization is complete, return to FIRST LINE to confirm the account, phone number, and connection status, then test sending and receiving messages.

If Meta does not allow deleting the phone number, do not force the creation of another duplicate setup.

Meta may temporarily disallow deletion due to billing settlement, phone number status, or recent message usage. If the delete button cannot be used, first handle the restriction shown on the WhatsApp Manager screen or wait until the restriction is lifted before trying again.

Some accounts may encounter a restriction such as “there has been recent paid message activity, so the phone number cannot be deleted for now.” If Meta shows that you need to wait a certain period, follow the deadline shown on the Meta screen, and try again after that period expires.

After successfully deleting the phone number from WhatsApp Manager, the number will be released from the original official WhatsApp account. You will still need to go through FIRST LINE’s embedded registration and phone number verification/registration process again before it can be used in the new connection method.

Not sure which account was originally used?

You can confirm by following these steps:

1. Log in to the Meta Business Suite used by the company.

2. Go to WhatsApp Accounts in Settings, or open WhatsApp Manager.

3. Find the WhatsApp phone number currently in use.

4. Confirm which official WhatsApp account and Business Portfolio that phone number currently belongs to.

5. When you return to FIRST LINE for embedded registration, first confirm that the Business Portfolio and original phone number are correct; for the official WhatsApp account, follow the items actually available on the Meta screen.

If the Meta account you are currently logged into cannot see that phone number, first confirm that you are logged into the correct company Meta account and that the account has permission to manage WhatsApp assets. Do not delete existing WhatsApp assets first.

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FAQ

Can I use it immediately after completing embedded registration?

Not necessarily. After Meta authorization is completed, you still need to return to FIRST LINE to confirm the phone number information; in some cases you also need to perform phone number registration, and finally test sending and receiving messages.

For existing FIRST LINE WhatsApp Cloud API users, not all upgrade scenarios will automatically continue using the original channel. If the official WhatsApp account or phone number is remapped, FIRST LINE may still need to help with further handling.

What is the 6-digit two-step verification PIN?

This is the two-step verification PIN for the WhatsApp phone number itself, usually set by the person who originally managed that phone number.

It is not:

• The Meta / Facebook account password.

• The verification code received by mobile SMS.

• The one-time verification code received by voice call.

If the existing phone number has two-step verification set up, some phone number registration processes will require entering this PIN.

I forgot the 6-digit PIN, what should I do?

First go to WhatsApp Manager to find that phone number, check the two-step verification settings, and reset or update the PIN according to the method provided by Meta.

After resetting the PIN, return to FIRST LINE to perform phone number registration. Do not use your Meta / Facebook password or SMS verification code as a substitute.

Can I choose “Use a display name only”?

If this option is available on the Meta screen, you can complete the setup according to the screen. Meta may provide an available number, but the actual available scope and eligibility still depend on what Meta shows at that time.

If you are preparing for official external service, it is still recommended to use a phone number actually managed by the business.

I can’t see the original official WhatsApp account on the Meta screen. What should I do?

For accounts that originally used Direct Cloud API, the original official WhatsApp account may not appear in embedded registration.

Please first confirm:

1. Whether you are logged into the Meta account that originally managed the company’s WhatsApp.

2. Whether you selected the original Business Portfolio.

3. Whether the original phone number is still managed by the company.

If all of the above are correct, but the original official WhatsApp account still does not appear, you can create a new official WhatsApp account in the original Business Portfolio according to the Meta screen, and complete the transfer with the original phone number. The key is to keep the original Business Portfolio and original phone number, not to force a return to the original official WhatsApp account.

My phone number is currently being used in the WhatsApp Business App. Can I connect it directly?

This type of number is different from a new number that has not yet been used on WhatsApp. Before starting, first confirm whether you need to continue using the WhatsApp Business App, and do not delete the account or phone number in the app first.

After entering the Meta connection flow, handle the existing number according to the options provided on the Meta screen. If the screen does not provide a connection method suitable for the current number, exit the flow first and keep the original WhatsApp Business App setup to avoid directly creating another account to replace the existing number.

My phone number is currently managed by another WhatsApp provider. Can I connect it directly?

This type of number usually needs to be transferred through Meta’s Migration / Transfer process instead of being created as a new phone number.

Before starting, please first confirm:

• You can still log in to the Meta Business Portfolio that manages that phone number.

• The current phone number can still normally receive verification messages or calls.

• The original official WhatsApp account and phone number are still active; do not delete them first.

Then start embedded registration from FIRST LINE; when Meta recognizes the existing number and shows Migration / Transfer, complete the transfer and verification according to the screen.

What should I do if I can’t receive the phone number verification code?

If you are setting up with your own phone number, check the following in order:

1. The number can currently receive normal SMS or voice calls.

2. The company’s main phone system, call system, or telecom service is not blocking external verification calls or SMS.

3. The country code and phone number entered are correct.

4. If SMS cannot be received, you can switch to voice verification when Meta provides it on the screen.

If you have already tried repeatedly in a short time, please stop requesting verification codes repeatedly first, and try again later according to the Meta screen to avoid triggering additional restrictions.

Why does FIRST LINE show a phone number registration entry?

Currently, for accounts authorized through embedded registration and for which FIRST LINE has obtained phone number information, the screen may provide a phone number registration entry.

This entry allows you to perform Meta’s phone number registration process, but it does not mean that FIRST LINE has accurately determined that the number is definitely not yet registered. Whether it actually needs to be performed should still be judged based on the current Meta status and the actual send/receive results.

Will the original chat history disappear after upgrading?

Keeping the original FIRST LINE Channel and chat history is the goal of the upgrade, but it should not currently be assumed that all cases are automatically completed.

If the same WhatsApp asset is still used after the upgrade, the subsequent mapping is usually simpler; if the original official WhatsApp account is transferred to a new official WhatsApp account, FIRST LINE still needs to complete the remapping between the old channel and the new asset before the original channel and chat history can truly be continued.

Before FIRST LINE completes the mapping, please do not delete the original channel or existing WhatsApp assets.

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Still unable to connect?

You can first confirm according to the stage at which the issue occurs.

Unable to complete it on the Meta screen

Confirm according to where the issue occurs on the screen:

• Cannot find the Business Portfolio: confirm that you are logged into the company’s Meta account, and check in Meta Business Suite whether that account has Business Portfolio admin access.

• Cannot find the original official WhatsApp account: the original Direct Cloud API account may not appear in embedded registration. First confirm that the Business Portfolio and original phone number are correct, then decide whether to create a new official WhatsApp account as the transfer destination according to the Meta screen.

• Cannot find the phone number: go to WhatsApp Manager to confirm that the original phone number is still managed by the company and that the logged-in account has admin access to that number.

• Phone number verification failed: confirm that the number can receive SMS or voice calls, that the country code is correct, and check whether the company’s main phone system or telecom service is blocking the verification message.

• Don’t know the 6-digit PIN: go to WhatsApp Manager to check the two-step verification settings for that phone number, reset or update the PIN according to the method provided by Meta, and then return to FIRST LINE to perform phone number registration.

• Meta shows business information, account restrictions, or review issues: follow the corresponding business information, account quality, or verification page in Meta to complete the required steps, then try connecting again.

Meta is complete, but FIRST LINE still needs follow-up settings

Please confirm in order:

1. Return to FIRST LINE and refresh the WhatsApp channel information.

2. Confirm that the Business Portfolio and phone number used this time are the expected ones.

3. If the screen provides a phone number registration entry, confirm whether you need to use the WhatsApp two-step verification 6-digit PIN to complete registration.

4. After completing the required settings, test sending and receiving messages.

At present, FIRST LINE should not be understood as fully tracking every status such as “authorized → pending registration → verifying → connected.” After the Meta authorization window is completed, it mainly returns to FIRST LINE and refreshes the account and phone number information, so please use the actual screen and send/receive test results to confirm whether it can be used normally.

Authorization is complete, but sending and receiving messages are abnormal

Please first test “customer inbound” and “FIRST LINE reply” separately:

• Neither side can send or receive: first confirm that FIRST LINE is still obtaining the expected WhatsApp account and phone number, and that the phone number in Meta is still in a normal state.

• Can receive, but cannot send: first confirm whether phone number registration still needs to be performed or the two-step verification PIN needs to be entered, then confirm that Meta does not show any restrictions related to the phone number, account quality, or message sending, and retest a normal text message.

• Can send, but cannot receive: use another WhatsApp account to resend a normal text message, and confirm that you are testing the phone number currently connected to FIRST LINE.

If the issue is still abnormal after the above tests, record the test time, the test phone number, which direction failed to send or receive, and the message shown on the screen, and provide it to FIRST LINE support for troubleshooting.

Meta shows Migration / Transfer

If you were originally a FIRST LINE user and Meta shows Migration / Transfer, do not assume that the wrong account was selected first. The original official WhatsApp account for Direct Cloud API may not appear in embedded registration, so it may be necessary to transfer the original phone number to a new official WhatsApp account under the same Business Portfolio.

Please first confirm:

1. The Business Portfolio is the one originally used by the company.

2. The phone number being transferred is the original one in use.

3. Keep the original phone number and the existing FIRST LINE Channel; do not delete them yourself.

If the phone number was originally managed by another WhatsApp provider, Migration / Transfer may also be the transfer process for an existing number. Please complete the transfer and phone verification according to the Meta screen.

To avoid affecting the WhatsApp currently in use, do not delete the official WhatsApp account, Business Portfolio, phone number, or original FIRST LINE channel yourself during troubleshooting or upgrading; only in the specific situation described on this page, where the original number was created from Meta Developer Portal and embedded registration cannot continue to use it directly, should you remove the phone number according to that section’s steps after confirming that the original phone number must be released.

Common Meta management links

If you need to confirm the Business Portfolio, official WhatsApp account, phone number, or admin access, you can directly use the following official Meta entry points:

• Meta Business Suite: view and switch the Business Portfolio currently used by the company.

• Meta Business Settings: manage the Business Portfolio, users, and business asset permissions.

• WhatsApp Manager: view official WhatsApp accounts, phone numbers, two-step verification, and other WhatsApp settings.

After opening the above Meta pages, first confirm that you are currently logged into the correct Meta account, and switch to the Business Portfolio actually used by the company. If the same Meta account manages multiple companies, the official WhatsApp accounts and phone numbers you see will differ depending on the currently selected Business Portfolio.