Do I need a new phone and a new SIM card for 5G?

5G mobile networks are already live in many countries, and more and more people are starting to buy 5G cellular services. We see a new cellular technology roughly every ten years, and every time there is a new technology, people have some basic questions surrounding the SIM, device and services. It is important to make all the necessary checks before buying yourself a new shiny 5G phone. This post aims to answer the most fundamental questions you need to think about to access the 5G network services.

As a customer, you need a new 5G compatible (5G ready) mobile phone to access 5G NR networks and, depending on your mobile operator, you may also need a new 5G SIM card. Your 5G phone will continue to work on earlier technologies, including 4G LTE, 3G UMTS and 2G GSM in areas with no 5G coverage.

What does 5G mean for you as a user?

We have been using 4G services for many years, and our phones seem to be doing their job just fine, so why do we need new technology, and why are we expected to pay a lot of money for it? 5G is the latest generation of mobile networks enabled by a new technology New Radio – NR. The G in 5G stands for Generation, and 5 represents the generation number. So 5G is the fifth generation of mobile networks, which is the next step after 4G LTE networks. 5G will play a key role directly and indirectly for most of us, but as a phone user, the most important aspect may be the higher download and upload speeds that 5G brings to the table. 5G NR technology can provide an average download speed of around 150 Mbps (Reading/UK/Dec 2021), which is higher than the average UK home broadband speed. So if you work from home frequently and have issues with your home broadband, 5G on your phone can provide a great backup solution if you want to use it as a mobile hotspot. The other, more exciting way of using 5G is to use it as your primary home internet. Have a look at our dedicated post on the average 5G speeds to find out how fast 5G is for an average user. You may also check out our post on 5G as your home internet to learn what 5G can do for your home broadband.

Does 5G require a new phone?

Yes, 5G uses New Radio (NR) which is a new technology and different from LTE (Long Term Evolution). If you want to access the 5G network, you need a 5G compatible mobile device. If you currently have a 4G LTE phone or broadband router, you cannot access the 5G network unless you upgrade. Upgrade means buying a new phone because 5G requires new hardware and software on your phone. It is important to note that all mobile devices are backwards compatible but not forward compatible. That means if you have a 5G phone or router and if you don’t have great 5G coverage in your area, you will still be able to access the 4G LTE network.

Will my 4G SIM work in a 5G phone?

One of the most frequently asked questions on 5G is about the SIM card and whether or not you need a new SIM to access 5G services? It is probably a confusing topic because different mobile operators have different stances. Interestingly all the different answers are technically accurate, making the topic slightly more confusing than it should be. So, let’s simplify it here. The short answer is that you do not need a new SIM for 5G, and your existing 4G SIM will work in your 5G phone; however, there may be some limitations.

The SIM card used in 4G networks is based on the same specifications as the 3G SIMs (USIM), making them backwards and forward compatible. The SIM card is an integrated circuit that is a combination of hardware and software. Your mobile subscription’s privacy and security aspects get more advanced as new technologies come, and 5G also adds new levels of security. So, if you use a 4G SIM in your 5G phone, it will technically still allow you to access 5G, but the levels of privacy and security will depend on what programme sits on the SIM. As a result, you may find mobile operators in the UK, who will advise you to get a new SIM for your 5G phone, but you may also find operators who will advise you otherwise. If a friend of mine asked for advice on this subject, I would say go for a new SIM card to be on the safe side.

Does 5G SIM work on any phone?

If you have a SIM card advertised as a 5G SIM, it will still work in older mobile phones, but you will not be able to access the 5G network on older phones. SIM cards from 3G onwards are backwards and forward compatible, so a 5G SIM will work in a 4G phone, but you will only get access to 4G, 3G and 2G networks when using a 4G phone. The other practical thing to keep in mind is to have the correct SIM size for your device. Nowadays, most operators provide a triple SIM that includes standard, micro and nano SIM sizes. So, for example, if your phone only takes a micro SIM, you want to make sure that you have the micro SIM size available. You may check out our dedicated post that explains what 5G technology means for your existing 4G phone and what services you can or can’t access.

What are the requirements to access 5G?

We have put together a quick and simple diagram to help you visualise what you need to think about when procuring 5G services. Essentially you need a 5G device, a SIM that works on 5G, a 5G mobile plan and 5G network coverage in your area. Below is a checklist and the necessary details for each item on the list.

  1. 5G coverage
  2. 5G mobile phone
  3. 5G tariff
  4. 5G ready SIM
SIM, Phone and Network for 5G
A checklist for getting 5G services

5G Network Coverage

The first thing you need to do is to find out whether your mobile operator has decent 5G coverage in your area or not. The best way to do that is by contacting the operator or checking the coverage map on your operator’s website. If you find out that your home or work location where you want the 5G services are not yet covered, the operator may be able to give you an idea of the timelines if you contact them. If you live in the UK, you can use the following links to check the mobile network coverage in your area.

Vodafone UK network coverage

EE network coverage

O2 network coverage

Three network coverage

If your current mobile service provider is not listed above, you may be using the services of an MVNO. MVNOs are Mobile Virtual Network Operators (e.g. Tesco Mobile) that use mobile networks of Mobile Network Operators (e.g. O2) to reach your phone. Here is a Wikipedia link to find out which MVNOs in the UK are using which mobile operators. The “Host network” column shows the mobile network operators (MNO).

5G Device

5G uses an entirely new access technology called New Radio (NR), which differs from what 4G uses. 4G networks are based on the LTE (Long Term Evolution) technology. So to access the 5G network, you need the necessary hardware and software that is compatible with 5G NR. Since all mobile cellular technologies are backwards compatible, your 5G device (phone or router) will also allow you to access 4G LTE and 3G UMTS/HSPA. 5G networks work in two modes; NSA (Non-Stand-Alone) and SA (Stand-alone). The NSA mode is more common at the moment, and it uses both 4G and 5G networks simultaneously to improve your data rate. This capability is called dual connectivity, which is something that 4G phones can’t do.


As 5G is still new and the coverage isn’t as mature in most parts of the world, your mobile operator may not have 5G available on all tariffs. They may sell both 4G and 5G tariffs separately so that people who live in areas without 5G have a cheaper option in the form of 4G tariffs. If you want 5G, make sure to check your plan before buying. When 5G becomes more common, you may get 5G on all tariffs as a standard. That depends on each operator as to how long it takes and how they want to sell 5G services in your country. Also important to check that there aren’t any “limitations” such as throttling or speed cap.


You may or may not need a new SIM card to access 5G services on your 5G phone. As explained above, some operators advise you to use the same 4G SIM, but some other operators advise customers to buy a new 5G SIM. Technically, your 4G SIM should be able to access the 5G network, but you should check with your operator. The preferred option is to get a new “5G Ready” SIM from your operator to be on the safe side.


You will need a new 5G compatible (5G Ready) mobile phone to access the 5G networks because your old 4G phones will only be able to connect you to 4G, 3G and 2G networks. You may also need a new 5G ready SIM card for your new 5G phone unless your mobile operator advises you otherwise. Mobile phones are backwards compatible, so your 5G phone will still allow you to automatically connect to 4G, 3G and 2G networks if you are in areas with limited or no 5G coverage.

Here are some helpful downloads

Thank you for reading this post, I hope it helped you in developing a better understanding of cellular networks. Sometimes, we need some extra support, especially when preparing for a new job, studying a new topic, or maybe just buying a new phone. Whatever you are trying to do, here are some downloads that can help you:

Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy, which explains the network nodes, e.g., BTS, MSC, GGSN etc.

Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and the challenges considering how quickly the industry evolves. The bigger picture comes from experience, which is why I’ve carefully put together a few slides to get you started in no time. So if you work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on the product overview and product roadmap.

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