First, make sure you have the most up-to-date version of the Facebook for iPhone app. Go to the App Store on your iPhone, and check the Updates section. If there's a newer version of the Facebook app you don't have yet, it'll be listed there for you to download.

If you continue to have trouble with the app, check the Facebook for iPhone Page for the most recent updates on known issues and new builds. If your problem isn't listed, please submit a report.

First, make sure you have the most up-to-date version of the Facebook for Android app. Go to Market > My Apps > Update. If there's a newer version of the Facebook app you don't have yet, it'll be listed there for you to download.

If you continue to experience difficulty with the application, check the Facebook for Android Page for the most recent updates on known issues and new builds. If your bug is not listed and you would like to submit a report, please click here.

Some people are unable to log in from their mobile phone and are receiving multiple errors. Please submit a report here.

This is probably a cache and cookies problem. To fix it:

1. Clear your mobile phone’s cache and cookies. Each phone is different, but you can usually clear cache and cookies from an option or settings menu when your mobile browser is open. You can consult your phone's user guide for more help.
2. Enter m.facebook.com as a new URL, rather than using a bookmark or a link. Log out of Facebook if you have the option.
3. Enter your normal login details to log in. Please note that passwords are case sensitive.

Note: You may to repeat steps 1 through 3 a few times.

If you get an error that your mobile number is already registered when you try to add it to your Facebook account, let us know. Make sure to provide your mobile number, including the country code, in your report.

This problem is related to technical issues experienced by your mobile carrier and we are working with them to resolve it as quickly as possible.

Some people are experiencing issues of receiving texts when logged in. Please submit a report here.

First, make sure that you have already activated Mobile Texts. If you are receiving texts but are having trouble sending them, please read the following guidelines to troubleshoot your problem:

• Check that you are sending your texts to the correct number. You can find this number on the Mobile Texts page.
• Make sure that your phone does not include a signature at the end of your texts. This can interfere with Facebook Mobile correspondence.
• Be sure that outgoing texts are still included in your service plan.
• If you are receiving error messages when you try to send your text, it may be due to problems with your mobile service provider. Please try contacting your service provider for help.

If none of the above information resolves your issue, click here to submit a report about your issue.

First, check the Mobile page for more information about whether your carrier is supported. Your carrier is supported if it is listed in the drop-down menu that appears when you click "Sign Up for Facebook Text Messages."

If your carrier is not supported, we encourage you to contact your carrier to let them know that you are interested in this service. If enough people show interest, they may decide to support our Mobile Texts feature. For now, please note that you can use our Mobile Uploads feature to upload photos, videos, and notes directly from your phone. You should also be able to access your account via Mobile Web at m.facebook.com or iphone.facebook.com for iPhones.

If your carrier is supported, please read the following guidelines to troubleshoot your problem:

• Be sure you are sending your text to the correct number for your carrier.
• Make sure that your phone does not include a signature at the end of your text messages. This can interfere with Facebook Mobile correspondence.
• Try sending "On" or "Fb" (without quotes) instead of "f" to receive your code.
• If you have recently ported your number from a different carrier, you may not be able to receive the confirmation code to activate Mobile Texts. This is a problem that we are aware of and hope to resolve it as soon as possible. We apologize for any inconvenience.

If none of the above information resolves your issue, please click here to submit a report about your issue.

If you're having trouble receiving a code to verify your account you can request a new code. There are two ways to do this:

• Click the Verify link under the captcha (words in the box) that you see when sending friend requests.
  
  
• Enter your mobile number on the mobile confirmation page. Choose your country code, then enter your number without any special characters (+ or -) or leading zeros.

Note: If you see a message that says you have reached the code limit, please wait a couple of days and try again. If you've tried both of these options and you are still unable to receive a code, let us know.

You can enter your confirmation code here.

This is a security measure to help ensure that Facebook remains a community of people using their real identities to connect and share. If you ever lose your password, you’ll also be able to use your mobile number to access your account.

To access your Facebook account, just follow the on-site instructions to add your mobile phone number.

If you are an iPhone user, simply use the Facebook for iPhone application available for free from the iTunes App Store.

If you are using your personalized uploads email address, please try refreshing your email address by following these instructions:

1. On the computer, go to the Publisher located at the top of your Wall (timeline) and click the Photos button next to "Attach."
2. Select "Upload a Photo."
3. Click the "upload via email" link.
4. Click the "refresh your upload email" link.

A dialog box will appear with your new personalized upload email address. Be sure to save this new address as a contact for easy access.

If the above information does not resolve your issue, and you would like to submit a bug report, please click here.

If you are not using your personalized upload email address or uploading through the Facebook Mobile website (m.facebook.com), you are most likely using the Facebook for Blackberry ® smartphones application, which is created and operated by outside developers. Unfortunately, Facebook cannot provide support for applications created and operated by outside developers. If you continue experiencing issues, we recommend contacting the application's developer for further assistance:

1. Go to the Facebook for Blackberry ® smartphones page.
2. Click the "Contact Developer" link on the bottom left hand side of the page.

In the meantime, note that you can always use your personalized upload email address to email a photo or video from your mobile phone. The uploaded content will appear in your Mobile Uploads album.

Although we're unable to reply to every bug report at this time, we may contact you for more details about the issue as we investigate the report. Thank you for taking the time to improve the site.

Please submit bug reports only here.