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The Subscriber Identity Module (SIM) that is a part of almost any smartphone is an integrated circuit that stores valuable data. Both your device and provider need this data as a way to authenticate your phone once it is part of a particular network. Additionally, your SIM card stores the personal data you input into the device. 

Most SIM cards tend to last for the life of a phone or the length of a subscriber’s contact with a provider. However, some situations might force a user to switch phones or numbers. It is common to get new SIM cards when you upgrade devices in this way, but some users wonder if it is possible to use their original cards again.

Today’s article will show whether you can use old SIM cards again. We will also figure out what happens to your old card once you put a new one on your phone. 

Depositphotos_265358660_S Close-up Of Sim Card And Smartphone on rough background

What Happens to Your Old SIM Card When You Get a New One?

The proper answer to this question depends on your choice after getting a new SIM card. You might find yourself in either of these common scenarios.

New SIMs and Providers

Although unlikely, you may want to activate a new SIM and a new plan with a different provider. If you choose this, you will have to end your subscription with your existing or old provider.

But you also have the option to keep both services active. That gives you two active SIM cards from different telco providers. So you will enjoy two connections as long as you pay your phone bills. 

Most people do not maintain two phones from different providers. However, it might be necessary if you are traveling and need data on another network. Another way to fix this problem when traveling is to purchase a plan from the local provider of your location.

Once you insert the card, you can use that carrier’s network to have your phone function as it would normally. Some other charges or restrictions may apply, but this is one way for international users to maintain smartphone service. You can swap the SIM cards with your old ones when you come home. 

Different SIMs With the Same Network

If you get a different SIM card with your existing network, your provider will deactivate your old SIM. It can or cannot happen right away. Either way, your carrier will remove the Integrated Circuit Card Identification Number (ICCID) of the old SIM from its records. 

The ICCID is an identifier that enables you to connect with a network provider. Once removed, the old SIM will no longer work. Instead, the carrier will add the ICCID from the new SIM card to its records. After that, they will pair this identifier with your phone, and you will use the device just as you did when the original SIM was inside it.

Can a SIM Card Be Reused?

The possibility of reusing a SIM card depends on the situation. You can reuse the old SIM in your existing account if you have a new device. It is similar to the scenario we mentioned earlier. The difference, though, is you use the old card on a different device rather than getting a new SIM. 

Note, however, that reusing an old SIM card after some time has passed may not be possible. If it is, it will depend on a few factors.

Some companies might allow you to insert and use an old SIM card on an updated contractual account

In such a case, you could use the old card as you usually would. However, this feature is less common on prepaid accounts, so it may not be possible if you keep this kind of account. Additionally, many companies will retire SIM cards after the card remains inactive for a long time. 

You’ll need a different or new SIM card to continue getting service from the company of your choice. The timelines for this deactivation could vary, but you can try your old SIM to see if you can reuse it. Deactivation is a more immediate concern if you should lose your card.

Do I Need My Old SIM Card To Keep My Number?

In most cases, you should not need to keep your old SIM card in your existing phone number. It’s because carriers tie specific phone numbers to particular SIM cards. It is part of the identification process of the card. 

Some providers offer SIM replacement features, which you can take advantage of. For example, with SIM replacement, you can ask your carrier to assign your current number to your new card. At some point, the old card will cease to function. However, the new card will maintain your phone number and data.

On a related note, you may be able to keep your old number when you switch providers. Changing service providers means that the new company will send you a SIM card of its own. 

However, most businesses know how keeping your old numbers is essential for their business. Therefore, it is an excellent way to save time and effort storing your contacts in your new number. 

You can ask your current provider to release your number for these scenarios. It is a process that may take a few minutes or a full day, but you will get an alert once complete. After the process, you can sign up for service with your new provider, informing them that you’ll be migrating your current number to their network.

Depositphotos_267547526_S Nano Sim Card In The Card Adapter With Eject Pin

Are Old Sim Cards Worth Keeping?

Although this is a personal decision, old SIM cards are not usually worth the effort or storage space. In addition, most of these cards will not work at some point due to the network provider deactivating them. However, there are a few niche angles to consider when keeping the old cards around. 

For one, storing digital documents or other small bits of data on such a card is still possible. Of course, you would not be able to use the SIM for its original purpose, but it may have some use this way. However, there are still more effective storage methods at your disposal.

Suppose the SIM card has some credit for data remaining once you upgrade to a different one. In that case, you may consider donating the money that makes up that credit to a charity of your choice. Often, you can do this through a text message. After that, you can dispose of the card. 

If you have a plan with a sound pay-as-you-go system that offers inexpensive rates, this may be one reason to keep the old SIM. However, you’ll have to use that SIM periodically to remain in good standing with the company you might return to in the future.

How Do You Dispose of an Old SIM Card?

If you know that a SIM card is not active, it is usually safe to throw it away. However, should you wish to be extra careful, there are a few other things you can do. If you can incinerate the card safely, this is one way to ensure it is completely gone. Otherwise, you can cut it into different pieces to render it inoperable. Similarly, you can also smash it to ensure the circuits break up properly.


SIM cards are small pieces of tech that act as the backbones of most smartphones. They store important data, allowing users to get on and use the networks from which they purchase service plans. In most cases, you won’t reuse an old SIM card, mainly if the company has deactivated it already.

However, there are particular circumstances in which it may be beneficial to keep some of your old SIMs around, and you can read about them here in our article above. Once ready, you can also safely dispose of your obsolete cards.