You were going to call a friend you haven't heard from in a long time. Opening the address book of your smartphone, however, you had a bitter surprise: the number of the person in question is no longer present in the memory! The problem is that you have recently changed SIM and, most likely, the contact you would now like to recover is present on the old card.
You have thus recovered your previous SIM but now you do not know how to proceed: not being very practical in technology, in fact, you do not know how to see if the contacts are on the SIM and possibly how to retrieve them. That's the way it is, right? Then don't worry: if you want, I'll be here to help you and explain how to view - and possibly import - the contacts on a SIM, regardless of the phone in your possession.
There are some limitations only on the iPhone, but not such as to prevent you from reaching your goal (especially if there is a friend / relative who can lend you an Android phone for a few minutes, but, again, it is not an essential requirement). At this point, all that's left for me is to wish you a good read and a big good luck for everything. Find everything explained below!
Prima di enter the dettaglio della procedura su how to see if the contacts are on the SIM, you must make sure that the card in your possession is compatible with the smartphone in which you intend to insert it.
To date, the most popular SIM formats are the Nano-SIM (4FF) (the smaller one), the Micro-SIM (3FF) (the intermediate one) and the Mini-SIM (2FF) (the one with more generous dimensions, used only in old phones). To find out what type of card your smartphone is compatible with, check the slot size, the device manual or do a simple Google search with terms like [smartphone model] sim format.
In case you are dealing with a SIM in a format that is not compatible with your smartphone, you can adapt it. For example, for reduce a larger SIM to a smaller one you can rely on do-it-yourself, using manual cutting of the card (generally not recommended, as it is easier to damage the SIM contacts, making it useless) or a SIM-cutting device. Find more details in my tutorials on how to adapt Micro-SIM to Nano-SIM, how to adapt SIM to Micro-SIM and how to adapt SIM to Nano-SIM.