AT&T will axe its $10 for 1,000 text messages plan on Sunday. Engadget first reported the news, which an AT&T spokesperson later confirmed to multiple publications. Before Aug. 21, it might make sense for people who don't already have the plan to lock it in.

AT&T will let customers already under the $10 plan continue to use it, even if they switch phones. However, for new customers or existing customers under a different text plan, it will no longer be available.  

Instead, there will be only two options: a $20 unlimited text plan, or no text plan and pay at least 20 cents per text.

Having no text plan is an unwise option for most people; at a rate of 20 cents per text, $20 will only buy a user 100 texts.

Having a $20 unlimited plan, however, makes less sense to many people than having the $10 plan. (For some people, AT&T's old plan of $5 for 200 texts actually makes even more sense.)

The reality is that many users use less than 200 texts per month. An even greater number of consumers use less than 1,000 texts.

(In fact, many users under the $20 unlimited plan don't actually need it; they're simply paying a premium for the simplicity and peace of mind that comes with the word unlimited.)

One reason is that smartphone users, especially those on the BlackBerry, communicate using emails or chat messengers (like KakaoTalk) in lieu of text messages.   

However, because most of them know a few people with feature phones who text them, they have to do some texting (to respond to feature phone users) each month, but certainly less than 1,000 texts and perhaps even less than 200 texts.

So if you care about paying an extra $10 per month to AT&T and you either know you're about to join AT&T or are convinced that your $20 unlimited plan makes no practical sense, then you should consider locking in the $10 for 1,000 texts plan before Sunday.