I get a newsletter from Martin Lewis' Money Saving Expert web site. Today, amongst other things, he offers this...
"Do a five-minute benefit check-up. Benefits and tax credits aren't solely for the unemployed, the web stretches much wider than you think, usually up to families with a sub-£40,000 income (higher for those with specific needs, eg, disabilities). We've a special, detailed Benefits Check-up Tool that asks a range of questions, then lists what you're entitled to. Payouts will change in April, but being up and running now helps."
http://www.moneysavingexpert.com/family/benefits-check
As we know there are many people who do not claim what they are entitled to, but those with five minutes to spare [and may hear the wolves at the door] can (I hope) with this tool get some idea of the sums involved.