Yes, you can. As of April 6, 2024, the UK ISA regulations allow partial transfers of your current tax year contributions as well as the previous year ones.
In case you're transferring part of your ISA to us, we can accept partial cash and/or in-specie transfers.
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 (in-specie) transfers are currently available only in full.