If you’re an iPhone user on a limited AT&T data plan but had an unlimited one in the past, AT&T will let you switch back for free, the AP reports.

AT&T refused to comment on the loophole that they’re not promoting at all, but the AP was able to confirm it with some users. The limited plans went into place in June, 2010.

It only works if you had an unlimited plan in the past. To do it, just call up AT&T customer service at 1-800-331-0500 or 611 from your phone and ask for it.

But before you do, check your bill to see how much data you really use. Unlimited plans cost $30. There is a 200 MB/month data plan for $15, and a 2 GB/month plan for $25. If you don’t use more data than your limited plan provides and don’t expect on increasing your usage, there’s no need to spring for a more expensive plan that you’re not going to take full advantage of.

A loophole means unlimited data for AT&T iPhone [SF Gate]

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