Hi
You can only have one new cash ISA per year. If you have two or more, you will need to decide which to close, to bring yu back to one.
You can transfer from an older ISA to a new ISA this year. The maximum is still £20000.00.
If you have a previous years tax ISA and open a new cash ISA in this tax year, you can place a maximum of £20000.00 in the new cash ISA and still retain the amount in the old cash ISA.
Have a look at the guidance at
Individual Savings Accounts (ISAs)
and consider speaking to your ISA provider, who should have a more indepth knowledge.
Thank you