Some people report difficulty using a hashtag (#) in their Tweets, or that Tweets sent as replies aren't working as expected. We’ve listed some possible causes and how to fix them.
Is there a symbol in after the username?
If you write @TwitterSupport.123, your message will be sent to the account @TwitterSupport, not @TwitterSupport123.
Is there text or a symbol preceding the @ symbol?
If you write .@TwitterSupport or ?@TwitterSupport, it will appear as a regular Tweet, meaning all of your followers will see it in their timeline, rather than just you, the intended recipient and those who follow both of you.
Is there a letter preceding the @ symbol?
If you write 123@TwitterSupport or word@TwitterSupport, @TwitterSupport will not receive your Tweet. Mentions will not work with letters or numbers in front of the @ symbol. The @ symbol must be at the beginning of a Tweet or it must have a space directly in front of it in order for the mention to work.
Are your Tweets protected?
If your Tweets are protected, the person you're trying to mention has to be one of your approved followers in order to see your Tweet. For example, if @TwitterSupport has protected Tweets, @twitter won't be able to see their Tweets unless @twitter follows that account.
Are you looking for your replies?
If you’re not seeing your reply below a Tweet, it may be because of an outstanding technical capacity limitation. When there are an overwhelming volume of replies to a Tweet, our platform is unable to show all of these replies. However, if your reply is showing up in your timeline, the Tweet author can, in most cases, view your reply in their Notifications.
My hashtags aren't working
Is there a symbol or punctuation in or after the hashtag?
If you write #it’sfun, your message will be categorized under #it. Punctuation marks ( , . ; ' ? ! etc.) will end your hashtag wherever punctuation occurs.
Is there a letter preceding the hashtag symbol?
If you write 123#sofun or word#sofun, your Tweets will not show in searches for the hashtag #sofun. Hashtags will not work with letters or numbers in front of the # symbol. The # symbol must have a space directly in front of it in order for it to show correctly in searches.
Is the hashtag made up entirely of numbers?
If you write #1 or #123 the hashtag will not be hyperlinked and is therefore not searchable. However, if you include letters following the numbers in the hashtag, for example, #123go, then the hashtag will work correctly.