The reason for this deadline is the change to pension rules introduced on April 6, 2006, known as A-day. That was when the government brought in a cap on how much tax-relieved pension saving you can make, known as the lifetime allowance, of £1.5m, which has now risen to £1.65m. Any pension above the lifetime limit is taxed at 55%.

On A-day, anyone with pensions worth more than the lifetime limit were offered two ways to protect what they had accrued, and the closing date for both is next April.

Primary protection allows savers to have a lifetime limit as big as the value of their pension on A-day and increase it at the same rate as the regular lifetime limit is raised. So somebody with a £3m pension fund at A-day can register for their lifetime limit to be protected at twice the regular lifetime limit, meaning today their lifetime limit will have risen to £3.3m, double the current £1.65m.

Alternatively, by electing enhanced protection at A-day, those whose pension was worth more than the lifetime limit could protect any investment growth in their fund provided they made no further contributions into it. Therefore, someone with a £2m fund at A-day whose fund grew to £4m by the time they retired could still get £1m tax-free and take the other £3m subject only to income tax.

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