Hi All,
We have just booked flights with BA from Manchester to Miami with a change at Heathrow. Has anyone done this route and can they advise on a couple of questions please.

In London either on the way out or the return leg will I have to collect the cases and re check them in or will they be transferred automatically to the final destination?

I think on both legs we have to transfer between terminals 3 & 5 at Heathrow, what does this involve?

Thanks in advance, any help or info will be helpful, we have never used BA before