At least 22.5 million households will be better off thanks to policies introduced by his Tory government, David Cameron is due to claim today - hailing what he will call "money-back Monday".
Kicking off the second week of election campaigning with a speech in the south west, the Conservative leader will argue that the Tories are the party of "low taxes".
Among the measures being brought into force today include raising the personal allowance to £10,600, a tax break for married couples coming into force, and the state pension rising 2.5%.
Annual ISA limits will be hiked dramatically, and working age benefit rises will be capped at 1%, he will add.
In a bid to counter Labour accusations that ordinary working families are not benefiting from the economic recovery, he will point to Treasury figures which suggest that 94% of households will be £200 better off a year thanks to Tory policies.
The figures also appear to show that the highest-earning tenth of the population will benefit the least, while middle-income families will be best off.
Today is a big day for our country. It's 'money-back Monday' - a day when, quite simply, hardworking taxpayers get to keep more of their own cash. A whole host of changes to our tax, benefits, pensions and savings systems come into effect today.
Chancellor George Osborne will appear alongside the Tory leader to try to encourage voters to choose the Conservatives, warning against what he will claim would be "many tax rises" under a Labour government.
In a year's time, at the start of the next tax year, we can either continue this progress under a Conservative government led by David Cameron.