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What to Backup Before Changing SIM Card?

Written by, Nikola Dimovski

Updated July, 18, 2023

Although SIM cards do not usually store information, it is possible that some data has found its way onto the card. To avoid losing valuable info, you will need to export the data before changing SIMs.

Here is the lowdown on what to backup before changing a SIM card, how to do it and what else you should think about before switching SIM cards between phones.

What to do Before Changing a SIM Card?

Before you switch your SIM card, you need to know a bit more about these cards and the kind of information they store.

What is a SIM card?

SIM cards are small computer chips that hold information and enable a subscriber to connect to a mobile network. Each SIM card holds an ID number that identifies your phone to the network, allowing you to make calls, send and receive SMS messages, as well as browse the internet through 4G or 5G connections. 

What is stored on a SIM card?

In the past, some SIM cards automatically stored some (or all) of your contacts. They could also store some information on data usage and certain apps, usually pre-installed by your provider. 

Today, though, contacts, texts, email settings, media files and apps are saved on your phone. And since only 5% of Brits say they have kept their old phone without buying a new one, chances of finding any essential information stored on a SIM are slim. 

Will switching SIM cards change anything?

When you replace your SIM card in your phone, you lose access to any data on the old card. Photos, apps, and other documents that aren’t stored on the SIM are not affected by the card switch. 

However, if you have data on your old SIM card and you haven’t transferred it to your phone or external storage, any phone numbers, addresses, or other data that are on it will remain there. To access them you would need to either

  • Insert the old SIM into a new device and transfer the data;
  • Back up the info before replacing the cards;
  • Opt for a dual SIM phone and use both cards on the same device. 

What to Backup Before Changing a SIM Card?

The most common data found on old SIMs are the phone numbers from your contacts list. The easiest way to back up this information would be to save your contacts on your device. These are the steps to follow depending on the type of phone you have. 

Changing SIM card in iPhone without losing data

Follow these steps to transfer contacts from a SIM card to your iPhone.

  1. Open the Settings application
  2. Tap on Contacts
  3. Select Import SIM Contacts at the bottom of the menu
  1. Choose where you want the contacts to be imported. 
  2. Check if the process was successful. Your contacts should be on your phone (if that is the option you chose) and then later synced to iCloud.

iPhones do not store contacts on SIM cards. If you need to move contacts from one iPhone to another, back them up on your computer or iCloud rather than on the SIM. 

Note: All iPhone users get access to Apple’s iCloud. If you haven’t used it so far, you might need to activate it to back up your files.

Change a SIM card without losing data on Android

If you’re not sure whether the contacts in your phone are saved on your SIM card, it’s best to copy all of them to the Android device you are using. To do so, you need to

  1. Open your Contacts application
  2. Select Settings, i.e, the three dots in the upper right corner
  3. Tap Manage ContactsImport/Export 
  1. Tap Import from SIM card

How to import contacts to Google Account 

You can also transfer contacts to your Google Account. Like Apple, Google allows users to sync their cloud storage but doesn’t require activation, as long as you’re logged into your Google account on your device. 

Google is more generous than Apple, providing users with up to 15GB of free storage, but if that’s not enough, you can always connect your phone to your PC via a USB cable and transfer all files there before inserting a new SIM card. Alternatively, you could transfer the contacts to an SD card. Simply choose the destination where you want your contacts to go when exporting them from the SIM. 

If I Put My SIM card in Another Phone, What Will Happen? 

You can put your old SIM card in another phone and retain the same number. You can then   use it to make calls, send texts, and use mobile data, provided that 

1. The phone is unlocked

If the phone is unlocked, fitting a new SIM card should not be an issue even if you are changing providers. Luckily, all phones sold in the UK since 2021 are unlocked.

That said, some providers used to lock their phones to their networks, so if you have an older locked phone, a new SIM card from another provider will not work. In this case, you will need to get it unlocked before you can use it. 

Note: You can easily check whether there are SIM restrictions by going to the Settings app. 

2. The SIM card fits 

Most phones nowadays come with micro or nano SIM cards. If you have an older standard SIM that is too big for your new phone, contact your network provider. They will send you a replacement SIM with activation instructions. 

If you backed up the information from your old SIM to the cloud, your email account, SD card or computer, you can easily copy the data from your old SIM to your new phone. You will need to activate the new SIM card first. 

Note: You might come across options allowing you to transfer SIM card data to another SIM card by cloning the old card and basically having two SIMs with the same number. Be careful, though—SIM card cloning is illegal in the UK

What Should You Consider Before Changing a Phone’s SIM card?

Data may not be stored on a SIM card, but your phone number may be linked to some apps, like Viber and WhatsApp.

What happens to Viber when you switch SIM cards?

Viber will detect if you have inserted a new SIM card on your device.

You can then decide between

  • Keeping the same number as the one attached to the SIM. Bear in mind that if your account is deactivated or you want to reinstall the app, you will need access to your old phone number (i.e. SIM) as the verification code required for the reinstall will be sent to that number. 
  • Using the new number on the new SIM. This way all your information will be kept and Viber will send a message to your contacts informing them that you have changed your number. 

What happens to WhatsApp if you change SIM cards?

Your WhatsApp should work normally if you change SIM cards between phones. However, if you want to get rid of your old number, you need to register the app with your new SIM card in place. 

Likewise, if you want to use the same WhatsApp account on a new phone, i.e. insert the SIM card in another phone, you should back up your chat history to the cloud and move your chats. If you have not done this before replacing SIMs, no need to worry—there are still ways to recover WhatsApp data.

What happens if your phone number is linked to other online accounts?

Users who receive verification and 2FA codes as SMS will need to update the information in their accounts when they switch SIMs. To do so

  • Turn off 2FA for each account it is enabled
  • Change your phone number
  • Turn 2FA back on
  • Enter your new phone number when asked where the SMS will be sent

This will make sure that you can log into your accounts, pay online and avoid the risk of losing any important data.

Note: This is required if you are changing the phone and SIM card or inserting a new card in an old device. If you simply use your old SIM in a new mobile, there will be no change. 

What happens to text messages when you change SIM cards?

Nothing. Your SMS messages are not stored on your SIM, so replacing the SIM on your device will have no effect on your texts. 

Frequently Asked Questions And Their Answers

What information is on a SIM card?

A SIM card contains your phone number and enables you to connect to the mobile network and thus make calls, send texts as well as connect to the internet via a 4G or 5G. On some older phones, SIM cards would also hold phone numbers from the contact list, however, today all information is saved on your device rather than the SIM. 

Can you copy a SIM card?

Yes, there is software that allows one to generate a duplicate copy of a SIM card, although SIM cloning is illegal in the UK. 

Does switching SIM cards transfer data?

No, switching SIMs will not transfer any data since no information is saved on a SIM nowadays. If you have some contacts or addresses saved on your SIM card and you insert it into another phone, the data will transfer as well. 

If you are using a new SIM card and you want to access the information on the old one, you need to go through the ‘what to backup before changing the SIM card’ checklist, move all the information you want to save on your phone and then activate the new card. 

My name is Nikola, and I’m an SEO Specialist and a tech enthusiast. I graduated from the Faculty of Economics, the department of E-Business Management. My experiences go from implementing ERP Solutions, CRM practices, and finally, on-page and off-page SEO. I take pride in staying ahead of the curve when it comes to SEO and keeping up with the latest changes to search algorithms. I love experimenting with new strategies and testing the results to see what works best. Outside of work, I enjoy tinkering with new tech gadgets and exploring the latest apps and software programs.