You can transfer part of your ISA only if the money you want to transfer was invested in previous tax years. If your ISA only consists of money invested in the current year, you cannot transfer it partially and must transfer the entire amount.
In case you're transferring part of your ISA to us, we can accept both cash and in-specie transfers. However, If you wish to move to another broker, we’ll be able to move your ISA partially only if the transfer is in cash. Stock transfers are available only in full.