How do I use Twitter on my phone? 

If you already have a Twitter account, you can access it from your phone using SMS or Twitter's mobile website, mobile.twitter.com. You can also create a new Twitter account via SMS by sending the word START to your Twitter shortcode.

Does it cost money? Will fees be added to my phone bill? 

Twitter is a free service; we do not charge you to use it, even via SMS. However, if you use Twitter via text message on your phone, your mobile carrier may charge you for those messages according to your service plan. Read more here.

What's a Twitter "short code"?

These are phone numbers that are used by Twitter to help you access your Twitter account via SMS on your phone. You can text message your Tweet to your respective code/number and it will post to your Twitter profile. Different countries use different codes. Find yours here!

Can I update Twitter from my phone but not receive other people's updates? And vice versa?

Yes. When you've attached your phone to your Twitter account, you will only receive updates from friends you've asked to get mobile Tweets from (learn about this here). When you send a text message from your phone to your Twitter code, it will always post as a Tweet to your profile.

I'm getting a ton of updates. How can I get fewer?

Turn off mobile updates from users you follow in one of these ways:

• Send commands from your phone to turn updates off for any people you follow by sending "OFF username" to your Twitter code.
• Send only the word "OFF" to turn all updates off until you choose to turn them on again (by sending the word "ON").
• Turn off mobile updates for any user from your web profile. Read more here.
• Additionally, you can set your Sleep Settings in your web profile to silence mobile updates for certain periods of every day.

I don't live in the U.S. How do I use Twitter on my phone?

We have short codes for many countries and carriers - texting one of these will allow you to Tweet via SMS. If your country is not listed here, you might want to use our one-way long code to post content to Twitter. Please note that all subscribers (even in the UK) may be charged international message rates.

You can also go to our mobile website, mobile.twitter.com from your phone's browser no matter where you are in the world (as long as you have cell phone reception on your smartphone!).

Want to know more? Check out Getting Started with Twitter via SMS.