As with so many things here in this service-deficient country, you ask two different people and you get two different answers. Even at the same office, same company. As a foreigner without residency, can you subscribe to a cell phone service with a monthly subscription that is cheaper than your current pay-as-you-go? Maybe. I have Nextel. It's not the cheapest per minute, but as part of the standard package they offer "free" CD Radio communication with other Nextel subscribers in addition to your allotted call minutes and text messages. This is useful if you are doing business here. Especially with taxi drivers, taxi boys, working girls, low level employees, etc., etc. I do have a CUIT, but I'm not sure it's necessary to have one in order to sign up. My advice is to keep trying until you find someone who gives you the answer you want.