There are certain set of frequencies, that are reserved, and some are "license free" You maybe thinking of the 446 allocation which is license free. However the frequencies you mention are not in these plans, and would require licensing in the UK.
How far Bulgaria has harmonized it allocations I don't know, but that band could be used for local civil comms. A lot of ex emergency services analogue equipment is finding new homes in Eastern Eu as forces move over to secure tetra/airwave type services.
One other thing to note, If the handsets are programmed with CTCSS, you may not hear any other comms, and cause interference to other users without knowing it. even if only upto 5W, giving 6miles LoS
One last note, Taking RF equipment over international borders can be a bit fraught, and -may- require full documentation. (I've know simple SW radios be confiscated...)
Just my -/6d worth