Income includes the state pension, other pensions earnings from employment and self-employment, as well as most other social security payments.
Those who have savings or a second pension, however, could be entitled to Savings Credit.
This will apply if someone has reached state pension age before April 6, 2016, and have saved some money for retirement.
Singletons can get up to £14.04 per week, with those in a couple getting up to £15.71 per week.
To be eligible for Pension Credit, a person must live in England, Scotland or Wales and have reached state pension age.