To check if you are getting your full means-tested benefits entitlement you may wish to use one of the Government's approved benefits checkers:
The main thing to watch out for is the severe disability premium (SDP). Check the following information to see if you're missing out on SDP:
Are you missing out on £76.40 per week?
If you are in receipt of Income Based Employment and Support Allowance (ESA), Income Support (IS) or Income Based Jobseekers Allowance (JSA) and are also getting:
Disability Living Allowance (DLA) middle or higher rate care component, or
Personal Independence Payment (PIP) standard or enhanced rate daily living component
Live without any other non-dependent adults in your household,
Have nobody claiming carers' allowance for looking after you,
Then you may well be underpaid by not being paid the Severe Disability Premium. If so tell the DWP and get advice if you have any problems.
There is also a couple rate of £134.60 per week if you have a severely disabled partner and no other adults live with you and nobody is claiming carers' allowance for either of you. You must both be on the qualifying rates of DLA / PIP.
Severe Disability Premium (SDP) is an additional amount on means-tested benefits. It is not a separate benefit. If you are in the above circumstances then you should get it from whenever these circumstances applied from, even it is many years.
There is no SDP payable for people on Universal Credit, although it can be transferred from ESA, so get yours now while you still can!