Yes! You can transfer a JISA from another provider into Freetrade’s Junior ISA. You can transfer as cash or as investments. If you’re transferring a stocks and shares JISA, you must transfer it in full. If you’re transferring a cash JISA, you can choose to transfer it in full (full transfer), or just a portion of it (partial transfer).
And transfers don’t use up any of the annual allowance.
Remember: a child can only have one cash JISA and one stocks and shares JISA at a time.