This has to be the best notification of a price increase I've ever seen (see first screenshot).

ING Direct  (USA) famously does not charge OD/NSF fees on its checking account, Electric Orange. But that's a bit of a moot point since the bank doesn't offer paper checks, making it difficult to inadvertently go negative.

However, the bank does allow overdrawing by few hundred dollars if you so choose. And it charges interest on those "overdrafts" at a variable rate equal to 4% above prime, currently 7.25%. The bank reinforces the no-fee pricing in its standard low-balance alert (see second screenshot below).

But that low APR is heading upwards. Last night I received an email notification that effective May 15, the variable rate will be increasing to 8% above prime, or 11.25% today, a 55% increase. That's still relatively reasonable for unsecured credit.

But the bank's email doesn't focus on APR. After clearly disclosing the price increase, it lays out a comparison of what a $100 overdraft would cost the average U.S. consumer for one week, $31, vs. the $0.31 you'd owe ING Direct after 7 days. There are no other fees, transaction or annual, for the ING credit line (complete terms here).

Well played.

ING Direct email disclosing OD credit line APR increase (21 March 2011)

Overdraft notice (22 March 2011)
The bank reinforces its no-fee policy in its email OD alert.