More than seven million UK households could be missing out on benefits like council tax discounts, according to analysis from online benefits calculator Entitledto.
Many benefits and discounts aren't granted automatically; depending on what you're eligible for, you'll need to apply to your local council or HMRC.
Here, Which? explains what kind of benefits you might be missing out on - and what to do if you're eligible to claim.
This is replacing legacy benefits such as tax credits, housing benefit, income-based jobseeker's allowance, income-related employment and support allowance, and income support - however, these legacy benefits are still available in some instances.
What you get depends on your circumstances, and it's still possible to claim even if you're working.
Child tax credit is for those on a low income who are responsible for at least one child or young person. You can only make a new claim for child tax credit if you already receive working tax credit.
As council tax bills are calculated on the assumption that two adults live in a property, anyone living alone can get a single-person discount and get 25% off their council tax bill.
Councils don't apply this discount automatically, so if you think you're eligible you'll need to apply through your local council.
However, those who don't live alone could also be missing out on this discount. That's because certain groups of people are disregarded for council tax purposes - so if you live with one or more 'disregarded' people, you'll still be treated as if you're living alone.
Disregarded people for council tax include 18 or 19-year-olds in full-time education, student nurses, people who are severely mentally impaired and apprentices studying for a recognised qualification. You can find a more extensive list .
If everyone in the household counts as being disregarded, you'll usually get a 50% discount.
If everyone in the household is exempt - for instance, if you're all full-time students - then you don't need to pay any council tax at all.
It will ask for things like your age, employment status, whether you have children, whether you have caring responsibilities and whether you already claim any benefits.
Based on your answers, it will then suggest benefits and discounts you might be able to claim.
The online tool is free to use, independent of the government and is often used by housing associations, charities and local government departments.