The first Beaus arrived on 25 Sqn in October 1940, but they were not operational on type, as they were still flying Blenheims. It takes time to convert, and the Squadron did not become fully operational on Beaus until January 1941.
The only Squadrons using Beaus operationally in the later stages of the BoB, were the two '600' squadrons, and then mostly after the 'official' end of the BoB, although some ops would possibly have been carried out in late October.
The F.I.U., who were experimenting with Airborne Interception (radar), had some Beaus on strength, as well as Blenhiem F1s, and operated from Tangmere, and other airfields.
Again, I refer you to the list mentioned previously. These are the only squadrons operational in the BoB, and the two units mentioned above are shown. A check of the unit histories will show their bases and aircraft/ops details.