Virgin Mobile really loves iPhone users … After going iPhone-only back in June, and offering a really sweet deal to those buying a new phone, it has now extended the offer to existing iPhone owners switching to the carrier.

The carrier says that any iPhone owner who ports their number to Virgin will be able to get the same ‘all you can eat’ $1 deal for a full 12 months …

After the first year, you’ll be switched to the company’s standard ‘unlimited everything’ plan, which costs $50 per month. The deal needn’t end there, though: you’ll get an additional six months of service for $1 if you upgrade to a new iPhone.

As we noted before, the usual carrier caveats apply: your data usage may be ‘deprioritized’ if you go over 23GB a month, and terminated altogether if you do a lot of roaming. To qualify, you’ll need an iPhone 5s or later, and the offer is subject to confirmation of compatibility with Virgin’s network.

Virgin says that the deal is open for a short time, but doesn’t specify a cutoff date.

It does say that there will be a $25 charge for the SIM from September 29.