Here is a quick summary of the key points:

• Be sure that you are opening the right type of ISA. If you are likely to want to invest more than £3000 in stocks and shares in any one tax year, you should open a Maxi ISA.
• You can only subscribe to one maxi ISA per tax year.
• You cannot subscribe to a mini ISA and a maxi ISA in the same tax year.
• You can subscribe to up to three separate mini ISA investing in each of the three different types of investment (stocks and shares, cash and life assurance) in the same tax year.
• You must not subscribe to more than one mini ISA investing in the same type of investment in the same tax year.
• Once you have subscribed to a mini ISA, no matter what it invests in, you cannot change it to a maxi ISA (or vice versa) part way through the tax year. You must wait until the beginning of the new tax year before swapping.
• You cannot switch between the different types of investment in your ISA. However, you can hold cash within the stocks and shares and/or life assurance portion of a maxi ISA, or within a stocks and shares and/or life assurance mini ISA, providing you intend to use it to buy stocks and shares and/or life assurance. However, this will not be tax free - a 20% charge will be deducted from any interest generated by this cash and paid to the Inland Revenue. Clearly this does not apply to cash held in the cash portion of a mini or maxi ISA.
• If you subscribe to a mini cash or life assurance ISAs, no matter how little you subscribe, you will only be able to open a mini stocks and shares ISA, which is limited to subscriptions of £3000 in that tax year.
• You can normally transfer your ISA to another investment manager at any time. You can transfer some or all of the value of your ISA contributions from previous years, but to transfer any of the current year's contributions, you must transfer the total value of any payments you have made that year.
• Remember that the value of many forms of investment can go down as well as up, and that past performance should not be taken as a guide to future growth.