Today is the final day for investors to make the most of their ISA allowance and marks the end of the 2011/12 tax year.

Many firms will be staying open late today to help advisers and individuals with final Isa payments.

To help with last-minute deals, Financial Planner Online has complied a list of deadline times for key companies.

• Aberdeen Asset Management:  By post/hand delivery until 10pm, online until midnight.
• Alliance Trust Savings: By post/hand delivery until noon, online until 11.59pm.
• Barclays Stockbrokers: Online until 11.30pm and by phone until 8.30pm for new Isa applications (not existing Isas).
• Fidelity: By post, phone or online until midnight, drop off applications at London Investor Centre, Cannon St until 7.30pm, Kingswood Fields, Surrey until midnight, Oakhill House, Tonbridge until midnight.
• Hargreaves Lansdown: Offices will be open until midnight.
• JP Morgan Asset Management:  By post/hand delivery until 5pm, online until 11.55pm and by phone until 5.30pm.
• Jupiter: By post until 5.30pm and by phone until 8pm.
• M&G: Online until 11.30pm and by phone until 11pm.
• Skandia: Lump-sum applications accepted until 5.30pm, offices open until 8pm for other tax-year end queries.

Individuals are allowed to invest up to £10,680 in their Isa although only £5,340 may be in cash, the remainder must be made up of stocks and shares.

This allowance will rise in line with inflation next tax year to £11,280.

New for 2012 are Junior Isas which are set up in a child’s name and have an investment limit of £3,600. This money will not be accessed by the child until they are 18.