In what US carriers can I use a Lumia 520?

[carloswin07]

I recommended this phone to a friend, but I don't know in which carriers in the US he will be able to use it if he buys it.
Does anyone know? Thanks!

 

[Kebero]

ATT, Aio, Straight Talk (with an ATT compatible SIM)

 

[carloswin07]

Also, he has metro pcs, could he use that?

 

[Laura Knotek]

Also, he has metro pcs, could he use that?

He'd be better off with a 521 if he has MetroPCS. MetroPCS uses T-Mobile's towers.

 

[Rad Matic]

Airvoice or H2O, both ATT MVNOs. The sims are $1 on eBay. I'm on Airvoice for $10/month. 250 mins or 500 texts or 150MBs. Auto-pay, rolls over. Just set up APN.