The vast majority of people do not defer taking their state pension, despite most being financially able to do so, losing out on as much as £19,000 extra retirement cash, according to research by Fidelity.
People could lose their entitlement to means-tested benefits if they spend their pension pots after taking advantage of pensions freedom, the government has warned.
The government must shed light on how incoming pension flexibilities interact with means-tested benefit rules, according to shadow pensions minister Gregg McClymont.
People will have to build up at least ten years of National Insurance payments or equivalent credits to be eligible for the single-tier state pension.
The government has won a key parliamentary vote on plans to cap benefit increases to 1% for the next three years.
Members of parliament are due to vote on Tuesday on controversial government plans to place a 1% cap on annual rises in some benefits and tax credits for three years.
Some 270,000 people have decided to opt out of receiving child benefit following changes to eligibility rules, according to the latest figures.