A phone number is required to be able to use WhatsApp, however if you don't want to provide your current number, you can use Google Voice to get a fake number. Google Voice is an anonymous messaging and calling service, unfortunately you'll need a phone number (yours or a friend's) to use it. This means that you need to have temporary access to a phone number to create a Google Voice account and be able to log into WhatsApp without using a phone number.
Steps
Part 1 of 2: Connect to Google Voice

Step 1. Open Google Voice
Go to this page in your computer's web browser. If you are signed in to a Google account, this will open the Google Voice setup page.
- If you are not signed in to a Google account, enter your email address followed by your password before continuing.
- Skip this step if you already have a Google Voice account.

Step 2. Find a location
Click on the text field in the middle of the page then type in a city name or area code (for example 503). As you type, you will see a drop-down menu with options appear below the text field.

Step 3. Select a location
Click on a city in the drop-down menu to choose it as the location for your Google Voice number.

Step 4. Write down your favorite number
You will see multiple phone numbers listed below the text field. Make a note of which one you want to use, as you will need it later to log into WhatsApp.

Step 5. Click Select
This is the green button to the right of the phone number you want to use.

Step 6. Click Validate when prompted
You will be redirected to the entry page for the number to be associated.

Step 7. Enter your phone number
In the text field that appears in the middle of the page, type a phone number that you have access to.

Step 8. Click Submit Code
This option is located at the bottom right of the phone number window. Google Voice will send a verification message to your phone.

Step 9. Get your code
Open your phone's messaging app, select the message sent by Google (usually a 5-digit number), and write down the 6-digit code in the body of the message.
The message from Google will say something like “Your Google Voice verification code is 123456”

Step 10. Enter the code
Type the 6-digit code into the text field in the middle of the Google Voice page.

Step 11. Click Check
This button is located at the bottom right of the code verification window.

Step 12. Select Claim at the command prompt
This will confirm that you want to use the phone number associated with your Google Voice account.
Depending on your phone number, you may not see this option. If so, go straight to the next step

Step 13. Click Finish when prompted

Step 14. Open the Google Voice page
If you're not automatically redirected to the Google Voice dashboard, click Google voice at the top left of the page.

Step 15. Click on the messages icon
It's the chat bubble logo at the top left of the dashboard. This will open your message history where you will later receive the verification code from WhatsApp.
Keep this window open for now
Part 2 of 2: Configure WhatsApp

Step 1. Uninstall and reinstall WhatsApp.
If WhatsApp is already on your phone, you will need to uninstall it first and then reinstall it to prevent it from remembering your user information.
If you haven't downloaded WhatsApp yet, please do so for your iPhone or Android before continuing

Step 2. Open WhatsApp
Tap the WhatsApp app icon that looks like a white chat bubble and white phone handset on a green background.

Step 3. Tap Accept and continue
This button is located at the bottom of the screen.

Step 4. Enter your Google Voice phone number
Tap the text field in the middle of the screen and then type in the phone number you chose for your Google Voice account.
- If you forgot to write down your Google Voice number, you can find it by opening the Google Voice dashboard, clicking on ☰ at the top left of the page, by selecting Settings then by going to the tab Phone numbers.

Step 5. Tap Done
This option is located at the top right of the screen.
- If you are using an Android device, tap FOLLOWING.

Step 6. Press Yes at the command prompt
This will confirm your phone number and ask WhatsApp to send you a verification message.
- If you are using an Android, tap OK.

Step 7. Wait for the verification message
On the Google Voice dashboard, wait for the verification message to be received. It should appear on the left of the page.

Step 8. Get your code
Click on the message on the left of the page then write down the 6-digit code in the message that appears on the right.

Step 9. Enter your code
Type your verification code in the text field. WhatsApp will process the number as soon as you finish entering it.

Step 10. Tap Skip Restore
It's the red button in the middle of the screen.
- On Android, tap Pass.

Step 11. Enter your profile information
Tap the text field Your name then type the name you want to use. You can also add a photo by tapping the circle Add a picture at the top left of the screen then selecting a photo.

Step 12. Tap Done
This option is located at the top right of the screen. Tap on it to create your WhatsApp account.
- Press on Following on Android.