AT&T has indicated that it is doing away with its 1000 message a month plan, offering new subscribers a more expensive unlimited plan (or pay-by-message fees) instead. The change phases in on August 21, 2011.

[ad#Google Adsense 300×250 in story]AT&T’s 1,000 message plan cost subscribers $10 per month. The unlimited plan costs twice as much for individuals and three times as much for family plans, which can be spread to up to five phones.

AT&T said in a statement that “the vast majority” of its customers who use message prefer unlimited plans.

AT&T won’t force existing subscribers to switch to a new plan. Your existing messaging plan can also be transferred to a new phone.

[Hat tip: Engadget]