The only limitation you should have on your Stocks and Shares ISA is your allowable yearly deposit which is just over £15k per tax year at present.
When and how you deposit this should be up to you, on my account it shows a balance and I can deposit all in one go, monthly or not at all if I wish.
When and how you deposit this should be up to you, on my account it shows a balance and I can deposit all in one go, monthly or not at all if I wish.