iPhone users are still tied to just one network in the US and UK
Its announcement comes after rival Vodafone went to a German court to challenge T-Mobile's exclusive tie-up with the iPhone in Germany.
T-Mobile will now sell people just the handset for 999 euros ($1,477; £719).
This is a significant premium over the 399-euro price for those who also take out a two-year T-Mobile contract.
Apple has similar exclusive iPhone arrangements with O2 in the UK and AT&T in the US.
T-Mobile added that customers could also now have the SIM lock on their iPhone removed, including those who have already purchased a handset.
This would allow them to switch to another phone network.
T-Mobile said in its statement that it would abide by the conditions "until the legal situation is resolved".