Generally in most cases you would only have Openserve and “Other fibre network”, I would check with your ISP on what there terms are but for us, we would like to keep our customers so we allow our customers to move from one network to another. The networks see this as a brand new customer though so they will charge us Activation and installations fees, which we can absorb on your behalf if we choose.
What’s most interesting to me on this, are you doing this because your moving house or staying in the same place where 2 operators pass your home, and fed up with your fibre cable operator, but happy with your ISP?