The prior replies have generally covered your question well. I would like to add something to think about if you have any mysterious problems once you get a new SIM/eSIM and a new local phone number.
I purchased a physical SIM in 2019 from Vodafone Spain. I provided my passport and an account was set up for me. Everything worked fine.
I returned in 2023 and purchased another SIM, provided my passport and my account got registered, I tested the data connection, found that it worked, I asked the Vodafone staff member to phone my new local number and my phone rang and so I didn't bother answering because the store was very busy and so I left. I had been impressed with how quickly the seemingly inexperienced Vodafone Spain employee had set up my account for me.
A couple of days later I went to phone someone and I found that the number would ring but as soon as someone picked up the phone at the other end my phone hung up. I tried this a couple of times with exactly the same result every time.
I wondered if the inexperienced Vodafone staff member had made a mistake and so using the data connection (which worked fine) I connected to my account using a web browser. Everything looked fine and so just in case it was some credit issue I put another €5 into my account using my credit card. This made no difference.
I went back to a Vodafone Spain store to get help but it was a different store and the sole staff member didn't speak English and I don't speak enough Spanish to explain my problem and so I used Google translate to try and explain my problem but the staff member wasn't interested in helping me and told me to go back to the store that I had bought the SIM from. This was inconvenient and so I went to a very large Vodafone Spain store off one of the main squares in Madrid where they get a lot of tourists.
This store was very busy and so I took a number from the queuing machine and waited just over an hour to be attended to. The staff member did speak very good English and I explained my unusual problem. They phoned my local number and observed the unusual behaviour but they could not figure out how to fix it.
I asked for a refund and was told that I couldn't get a refund because I had used the data. By this time I was getting somewhat upset and asked to talk to someone who had good technical knowledge rather than the first line customer support on the store counter. Initially they refused because the technical people only worked on problems for people with permanent monthly accounts with Vodafone Spain, not prepay customers like myself.
I persisted and eventually they relented and I got to see a techy guy. He once again verified that I had a problem then set about trying to figure out what was causing it. After about another hour he gave up as well and said that I should use WhatsApp if I wanted to make phone calls as my data connection worked perfectly.
By now I was really sick of the problem and so I accepted his advice and left the store.
About five days later my phone started working and I noticed it when someone phoned me and I was able to take the call.
I never heard from Vodafone Spain about how they fixed the problem but with hindsight and some knowledge of Vodafone's computer systems (I contracted to Vodafone ANZ at one stage in my career) I think that I know what happened.
The first Vodafone employee, the inexperienced one that seemed to set up my account really fast, looked me up in their system and found my account from 2019. This account still had a phone number associated with it even though the SIM card had expired.
The staff member used my 2019 account but forgot to change the phone number in one of the places to the new number associated with the new SIM card. The data connection is associated with the internal ID associated with the SIM card and so that worked fine because I was using the new SIM card but my old phone number was credited with the amount that I paid for the plan and so my new number had no credit associated with it and didn't work.
Typically, this is what happens if you use all your allocated talk minutes and there is no credit balance in your account. The phone will ring but as soon as someone answers it cuts out, no credit.
Meantime the information that is used to provide data for the online version of my account that I had accessed using a web browser was correctly linked to the new number and so it looked like I had a credit balance in my account!
So moral of the story, if you have had an account with the service provider before AND you happen to strike an inexperienced staff member when you go in to purchase a new SIM AND your phone doesn't work but data does then quite possibly someone has made a mistake with not populating your new phone number into all the required places.
Of course, in a perfect world Vodafone's back office computer systems would all be integrated and so they would only need to populate your new number in one place but the reality is that systems have been added over the top of existing systems and so, at Vodafone at least, when your account is renewed with a new SIM and phone number then that new phone number needs to be entered in more than one place and if that isn't done then you may get a very mysterious problem like me.
