The firm's Class of 2013 research questioned over 8,000 people including 1,000 who intend to retire this year.
The region most likely to rely on the State Pension is the East Midlands followed by the North West while the West Midlands relied on it least.
On average, State Pension will account for more than a third of a person's retirement income. This increased to 43 per cent for women and women were three times more likely to retire with a State Pension only.
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Nearly a quarter of people overestimated the State Pension payment by over £600 a year while 10 per cent said they had no idea how much it was.
Currently the maximum people can receive from the basic State Pension is £110.15 per week. However, there are plans to increase this to a flat rate of £144 per week under a single-tier plan for those who have worked 35 years.
Vince Smith-Hughes, retirement income expert at Prudential, said: "Against a backdrop of rising living costs, the basic State Pension alone is not nearly enough to provide a comfortable standard of living.
"While it's a very valuable source of additional income for millions of pensioners, the State Pension should ideally only represent a part of someone's retirement income-not all of it."

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