Probably not, but it depends on how powerful you need the radio to be.
Most countries have a regulatory body that governs the use of radio frequencies. They do this so that different groups can use radio signals without interfering with each other (especially in the case of the emergency services). Here in the UK, radio transmission is regulated by Ofcom (Office of Communications), which is, in turn, regulated by the UK government.
However, if you are only planning on using a small device, Ofcom do allow some ‘licence free’ walkie-talkies.
The UK government allows small, low-powered handheld radios that use a set of eight frequencies in the UHF band (around 446Mhz) to be sold and used without the need for any licensing. They may be used for both business and personal / leisure purposes. Radios that meet this standard (usually called “PMR446” radios) can only have a power output of 0.5 watts, which means that their range is less than the more powerful licensable business walkie-talkies, that have power outputs of 4 to 5 watts.
One of the benefits of the European Union is that the standard for license-free radios is exactly the same, right across the EU. This means that if your radio is license-free in the UK, it will also be license free anywhere else in the EU).
If you wanted to use a more powerful radio (say anything over 5 watts for a handheld or 25 watts for vehicle radios and base stations), then you will need a license. Licensed handheld walkie-talkies can have 5 watts power output, but “licence-free” PMR446 radios can only have ½ watt power output, so the licensed radios will have a better range and better signal penetration in buildings.
The most basic licence available to you would be the ‘UK Simple’ license,
This licence is effectively a licence to use the more powerful radios anywhere in the United Kingdom, using a set of frequencies that are shared by all users of this licence. This licence is quick and easy to apply for, costs £75 per organization, and is valid for five years. It is ideal for most users of business radios, and is the only choice for those who need to be able to use their radios anywhere in the UK.
It is also possible to get a ‘Technically assigned Geographic License’ – essentially, this license allows you to use a specific frequency (or set of frequencies) that are uniquely yours. The catch is that you can only use them within a specific location. These licenses aren’t especially expensive to maintain, but the cost is rising in major cities, especially London.
If you are setting yourself up as an equipment lender, or rental firm, then you’ll need a UK Simple Business Radio Supplier’s License. This license allocates you a set of frequencies that you rent out to clients, along with your own equipment. Because the frequencies are licensed to you, the hirer of the equipment need not worry about obtaining their own license.