Can I move cash from my AJ Bell Youinvest Stocks and shares ISA or Dealing account to my Lifetime ISA?
If the value of your current year account in your Stocks and shares ISA is more than £4,000, you won’t be able to transfer part of it over. This is because you can’t split your current year subscriptions between ISAs. You could however partially transfer any subscriptions you’ve made in previous years.
Payments from other accounts to your Lifetime ISA will still count towards your annual £4,000 payment limit, so you'll need to be careful how much you transfer.