Sky has commenced the process of swapping out its ten million smart cards, a procedure which is likely to take several months.
On air promotions were screened for the first time this week advising viewers of the change.
In addition to the letter that will be issued with the replacement card, Sky has also produced a microsite to guide subscribers through the process.
There is no immediate threat to the security of the NDS VideoGuard conditional access system and the procedure is thought to be nothing more than routine.
In total there are around 10.9 million Sky cards in use, 9.2 million subscribers, and a further 1.7 million issued to Multiroom households.