If you are using a DIY ISA Portfolio with the Autoinvest feature turned off, we do not require you to invest your cash balance in your ISA account. The cash balance will remain uninvested until you place your orders, or use either the Autoinvest or Rebalance feature.
You do not need to invest your current tax years allowance in order to keep that part of your allowance; what is important is when you make a contribution to your ISA. If you wish to take advantage of your current tax years ISA allowance, you must contribute to it no later than the cut-off time on the 5th April. You can invest those same monies in the new tax year, if that is part of your investing strategy.
If you have a Managed ISA portfolio; as with all our managed accounts your cash monies will be invested in the next available trading window.