As of February 2022, a number of amateur stations in the UK are trying to get permission from OFCOM, the UK licensing authority to carry out experiments on the 40 MHz band.
NOV... Roger, G3XBM reports that he applied for a Amateur Radio Special Research Permit and getting a Notice Of Variation (NOV) as shown in A above. His application for this was recently turned down.
At present, some UK radio amateurs are using these NOV's to experiment with compressed digital video techniques at 146 MHz and 71 MHz.
I know there is at least one more person waiting for a reply on their application for a 40 MHz NOV although it doesn't look good at this stage.
Innovation & Trial License... The second route is to apply for a Innovation and Trial License as shown as B above. This costs at least £50 and G3XBM is currently applying for one of these.
This would seem to be similar to how the FCC in the United States recently allocated special experimental permits to seven individuals.
OFCOM... A few years ago, the RSGB (Radio Society of Great Britain) held discussions with OFCOM about new frequencies and allocations. OFCOM were of the view that they would not allocate anything for 'more of the same'.
In other words, they're not going to allocate new frequencies for DX-ing, contesting or just talking to someone else down the road. Their view was that radio amateurs in the UK have more than enough frequencies for this and they're probably right.
Any new permit or allocation will have to show there is a genuine need for it. Radio amateurs experimenting with modern compressed digital video techniques and getting the signal to fit inside a limited band is a good example of this.
Looking forward... It's not looking great at the moment but it would be very useful if some UK stations were allowed to use the weak signal mode WSPR on low power on the 40 MHz band on an experimental basis. They would be unlikely to cause any interference to other users if they were just given say the ISM band of 40.670 to 40.700 MHz to experiment with.
This could be used to carry out propagation experiments as we approach the peak of the next sunspot cycle. As the solar flux increases, it's not always obvious where the maximum usable frequency is for the F2 layer of the ionosphere.
We know it's in the low VHF region but where? It's well above 28 MHz but below 50 MHz. Being able to do propagation research is where the real value of having an allocation at 40 MHz lies.
It seems likely that if an application is going to be successful then it will have to go into some detail as to how the experiments will be carried out and how any potential interference to other users can be mitigated.