Apple estimates that some 250,000 of the 1.389 million iPhones sold through the September quarter were purchased with the intent of unlocking them. The comments came from Apple COO Tim Cook during the company’s Q4 quarterly conference call with analysts.

During a discussion about the iPhone trajectory of sales, prior to and after the price cut, Mr. Cook said that he was very pleased with the price elasticity of the iPhone but declined to elaborate on the details of day to say to sales prior to and after the price cuts.

Immediately following, however, he did elaborate on the unlocking issue and said, "we were very happy with the elasticity that we saw. It enabled us to far surpass our expectation of hitting around 1 million units cumulatively by the end of the quarter. Some number of these were sold to people that have an intention to unlock and where we don’t know precisely how many people are doing that, our current guess is that there were probably 250,000 of the 1.4 million that we sold where people had bought them with the intention of doing that. Many of those happened after the price cut. We’re not going to project precise numbers."

When asked if the iPhones purchased with the intention of being unlocked and not subscribed to the AT&T network were not eligible for payments from AT&T, Mr. Cook said, "That’s correct. The payments on AT&T depend on being locked to AT&T, obviously."

The fact that nearly 20 percent of all iPhones that have been purchased so far were with the intention of being unlocked could explain the early reports of a discrepancy between Apple’s iPhone shipments and those activated with AT&T in the early days after June 29th.