Hiya,
I've had a look on the gov website and it said the you need registration with the HCPC and to do that your degree has to be approved by the HCPC, which means that your biomedical science degree has to be accredited by the IBMS for it to meet the standards. So basically, your degree has to be accredited by IBMS which they will check and then you also need to have a portfolio completed and once those 2 things are done, you register with HCPC.
Check the IBMS and gov website.
So yes, you're degree should be accredited because otherwise its going to cost you a lot (this could easily be 10k) just to do top up modules if your degree isn't accredited.
The one thing that I cant find, is whether you have to pay IBMS to assess your degree even if it is accredited (ik you pay £350 ish but I'm not sure if this goes for people who's degree is accredited). I think that you have to pay regardless, but I cannot find anything on the website.
I hope this helps!