Use of UK number ranges are defined by the The National Telephone Numbering Plan (Ofcom).
01/02 numbers are Geographical
07 numbers are personal
Technically it is possible to allocate any number to the SIM but this may be against the above plan and it would introduce complexity to mobile operator processes and support.
There are a number of technical workarounds offered to businesses some better than others.
The most common solution (BT/Voda Business etc) is to port to a VoIP product with call forward to the mobile and the use of a VoIP app for outgoing calls or simply a VoIP app for both. This provides businesses with the functionality required but the actual "landline" number is assigned to a fixed UK business address.