Why cant I login to facebook on my mobile phone ?

If you can't log in with your mobile number:

• Make sure you enter your entire mobile phone number, including the country code
• Leave out any extra zeros, plus signs (+) or other special characters

If you signed up for Facebook using your mobile phone, you can use your mobile phone number to log in on any device. If you still can't log in or forgot your password, request a new password.
Otherwise Use Your Email Address as Username And Password To Login !! I hope This Helps!!

Reset yuor password by following this advice:

https://en-gb.facebook.com/help/213395615347144

To safeguard user privacy, the Facebook login process requires the input of an email address, username or mobile number as well as a password.
While you may opt for the "Remember Me" and "Remember My Password" features on your personal device, there may be times when you need to manually log in to your account.
If you're not able to locate your account from the login page, there are several steps you can take to recover it.Invalid or Expired Email Address
1. If you no longer have access to the email address that is linked to your Facebook account because it is invalid or expired, locate your account by logging in with an alternative.
If you registered a username, enter it in the "Email" field on the login page.
Enter your password and select the "Login" button. If unsuccessful, type your mobile phone number in the "Email" field on the login page.
Enter your password and select the "Login" button.
This will work if you've registered for Facebook texts.
If unsuccessful, type an alternate email address in the "Email" field on the login page.
Enter your password and select the "Login" button.
If you are still unable to identify your account, complete and submit the "I Cannot Identify My Account" report, which you'll find at facebook.com/help.
Click "Browse Help Center Topics" in the left column. Click the "Login & Password" option under "Managing Your Account."
Click on "I Can't Remember Which Email Address I Use To Log In To Facebook" and click the link in option 5.
Click the "I Can't Identify My Account" link in the lower-left corner of the resulting page to access the report.
2 . After you've logged in, click the "Account Settings" option that appears in the "Account" drop-down menu in the upper-right corner of any page.
3. Click the "Change" link next to the "Email" option of the "Settings" tab.
View your current email settings and edit as desired to manage email addresses that can be used for login.
Invalid Password
4. Visit facebook.com/recover.php in your browser.
5. Enter your email address or mobile phone number in the "Email or Phone" field that appears at the top of the page or enter your Facebook username in the space provided.
If you don't know the email address, mobile phone number or username that is associated with your account, type your name and the name of a friend in the spaces provided at the bottom of the page and click "Search."
6. Type the words that appear in the resulting security box to authenticate your request and click "Submit."
7. If the information that appears on the resulting page matches your account, click the "Reset Password" option to access your account.

To safeguard user privacy, the Facebook login process requires the input of an email address, username or mobile number as well as a password.
While you may opt for the "Remember Me" and "Remember My Password" features on your personal device, there may be times when you need to manually log in to your account.
If you're not able to locate your account from the login page, there are several steps you can take to recover it.Invalid or Expired Email Address
1. If you no longer have access to the email address that is linked to your Facebook account because it is invalid or expired, locate your account by logging in with an alternative.
If you registered a username, enter it in the "Email" field on the login page.
Enter your password and select the "Login" button. If unsuccessful, type your mobile phone number in the "Email" field on the login page.
Enter your password and select the "Login" button.
This will work if you've registered for Facebook texts.
If unsuccessful, type an alternate email address in the "Email" field on the login page.
Enter your password and select the "Login" button.
If you are still unable to identify your account, complete and submit the "I Cannot Identify My Account" report, which you'll find at facebook.com/help.
Click "Browse Help Center Topics" in the left column. Click the "Login & Password" option under "Managing Your Account."
Click on "I Can't Remember Which Email Address I Use To Log In To Facebook" and click the link in option 5.
Click the "I Can't Identify My Account" link in the lower-left corner of the resulting page to access the report.
2 . After you've logged in, click the "Account Settings" option that appears in the "Account" drop-down menu in the upper-right corner of any page.
3. Click the "Change" link next to the "Email" option of the "Settings" tab.
View your current email settings and edit as desired to manage email addresses that can be used for login.
Invalid Password
4. Visit facebook.com/recover.php in your browser.
5. Enter your email address or mobile phone number in the "Email or Phone" field that appears at the top of the page or enter your Facebook username in the space provided.
If you don't know the email address, mobile phone number or username that is associated with your account, type your name and the name of a friend in the spaces provided at the bottom of the page and click "Search."
6. Type the words that appear in the resulting security box to authenticate your request and click "Submit."
7. If the information that appears on the resulting page matches your account, click the "Reset Password" option to access your account.
https://www.facebook.com/recover.php
Identify your Account
http://www.facebook.com/help/?faq=18012
How can I make sure I don't lose access to my account

To safeguard user privacy, the Facebook login process requires the input of an email address, username or mobile number as well as a password.
While you may opt for the "Remember Me" and "Remember My Password" features on your personal device, there may be times when you need to manually log in to your account.
If you're not able to locate your account from the login page, there are several steps you can take to recover it.Invalid or Expired Email Address
1. If you no longer have access to the email address that is linked to your Facebook account because it is invalid or expired, locate your account by logging in with an alternative.
If you registered a username, enter it in the "Email" field on the login page.
Enter your password and select the "Login" button. If unsuccessful, type your mobile phone number in the "Email" field on the login page.
Enter your password and select the "Login" button.
This will work if you've registered for Facebook texts.
If unsuccessful, type an alternate email address in the "Email" field on the login page.
Enter your password and select the "Login" button.
If you are still unable to identify your account, complete and submit the "I Cannot Identify My Account" report, which you'll find at facebook.com/help.
Click "Browse Help Center Topics" in the left column. Click the "Login & Password" option under "Managing Your Account."
Click on "I Can't Remember Which Email Address I Use To Log In To Facebook" and click the link in option 5.
Click the "I Can't Identify My Account" link in the lower-left corner of the resulting page to access the report.
2 . After you've logged in, click the "Account Settings" option that appears in the "Account" drop-down menu in the upper-right corner of any page.
3. Click the "Change" link next to the "Email" option of the "Settings" tab.
View your current email settings and edit as desired to manage email addresses that can be used for login.
Invalid Password
4. Visit facebook.com/recover.php in your browser.
5. Enter your email address or mobile phone number in the "Email or Phone" field that appears at the top of the page or enter your Facebook username in the space provided.
If you don't know the email address, mobile phone number or username that is associated with your account, type your name and the name of a friend in the spaces provided at the bottom of the page and click "Search."
6. Type the words that appear in the resulting security box to authenticate your request and click "Submit."
7. If the information that appears on the resulting page matches your account, click the "Reset Password" option to access your account.

To safeguard user privacy, the Facebook login process requires the input of an email address, username or mobile number as well as a password.
While you may opt for the "Remember Me" and "Remember My Password" features on your personal device, there may be times when you need to manually log in to your account.
If you're not able to locate your account from the login page, there are several steps you can take to recover it.Invalid or Expired Email Address
1. If you no longer have access to the email address that is linked to your Facebook account because it is invalid or expired, locate your account by logging in with an alternative.
If you registered a username, enter it in the "Email" field on the login page.
Enter your password and select the "Login" button. If unsuccessful, type your mobile phone number in the "Email" field on the login page.
Enter your password and select the "Login" button.
This will work if you've registered for Facebook texts.
If unsuccessful, type an alternate email address in the "Email" field on the login page.
Enter your password and select the "Login" button.
If you are still unable to identify your account, complete and submit the "I Cannot Identify My Account" report, which you'll find at facebook.com/help.
Click "Browse Help Center Topics" in the left column. Click the "Login & Password" option under "Managing Your Account."
Click on "I Can't Remember Which Email Address I Use To Log In To Facebook" and click the link in option 5.
Click the "I Can't Identify My Account" link in the lower-left corner of the resulting page to access the report.
2 . After you've logged in, click the "Account Settings" option that appears in the "Account" drop-down menu in the upper-right corner of any page.
3. Click the "Change" link next to the "Email" option of the "Settings" tab.
View your current email settings and edit as desired to manage email addresses that can be used for login.
Invalid Password
4. Visit facebook.com/recover.php in your browser.
5. Enter your email address or mobile phone number in the "Email or Phone" field that appears at the top of the page or enter your Facebook username in the space provided.
If you don't know the email address, mobile phone number or username that is associated with your account, type your name and the name of a friend in the spaces provided at the bottom of the page and click "Search."
6. Type the words that appear in the resulting security box to authenticate your request and click "Submit."
7. If the information that appears on the resulting page matches your account, click the "Reset Password" option to access your account.
https://www.facebook.com/recover.php
Identify your Account
http://www.facebook.com/help/?faq=18012
How can I make sure I don't lose access to my account

Go to option -> Forgot your password, under the login fields on facebook and recover your password by mail or mobile phone.

Normally you can log in to face book, through any mobile phone.
It does not matter, if you are using a different phone number.The face book site, takes no record of your phone number.
All you need to do, is to log in your email address,and your password .That is all you need, to access your account on face book.
i.e Neither the phone type nor the phone number matters.Just your correct email address and your correct password

put inb your email

it wont let me get on my page it gos straight to password and gos on a differant page