Yes, providing you don’t exceed the maximum annual investment allowance (above) you can add to the JISA at any time during the tax year. If you are not subscribing on a monthly basis by direct debit the minimum additional investment is £50. Any person can subscribe to the child’s JISA - including parents, grandparents, family members and friends. All subscriptions will be classed as gifts to the child, which means that once premiums have been added, under normal circumstances (except on early death or the diagnosis of a terminal illness), the funds cannot be withdrawn until the child reaches the age of 18.