What documents do you need to resolve a guarantee in Romania

A few days ago I have discussed about Apple's decision to relax the rules regarding resolving the warranty of an iPhone 4 purchased in an EU member country. Under the pressure of the European Union, Apple decided to offer customers the opportunity to solve any warranty problem with their Apple terminal in any of the member countries of the European Union, even in those where there is no Apple Store. In Romania, such a guarantee can be resolved at the companies Noumax si iStyle that offers service for Apple terminals, both are in Bucharest and from what I understand they are happy to repair your terminals that have a valid warranty.

Ok, you have an Apple terminal, you think you have a valid warranty, but what documents do you need to prove that your phone is covered by the warranty? Only by the phone serial written in Settings>General>About>Serial Number, or if you have a box, you can find it on the label on the back of the box. Any sold Apple terminal has a serial that is registered in the Apple system from the day of sale, so from then on the warranty period begins to "flow" and with the help of this serial the warranty information can be checked. You can check if your terminal is under warranty by simply accessing a this website.

UPDATED: It seems that at iStyle the warranty can only be resolved if you have the receipt or invoice that proves the fact that you purchased the terminal. If you don't have them, then the warranty can only be resolved if the store management agrees.