If the council is paying for some or all of your care, they should give you details of care homes in the area which accept the amount they’re willing to pay. This will be based on your care needs and your finances, which they will assess first. You should only be charged top-up fees if you’ve chosen a care home that is more expensive than your council says it needs to be. The top-up fee covers the difference.
The council has to show you that there’s a cheaper alternative available which would meet your needs before they can charge you top-up fees. If not, the council has to increase the amount it is prepared to pay. You won’t normally be able to pay your own top-up fee; it will normally have to be paid by a friend, relative, charity or similar.