A new report has recommended that income tax and national insurance contributions (NICs) should be brought closer together in order to make a tax system that is fit for the future.
However, some fear that the exercise in simplification could lead to a system of winners and losers, with some paying more in taxes and others paying less.
One of the biggest losers under the new system is likely to be some self-employed people, who benefit under the current system of NICs.
The report from the Office of Tax Simplification (OTS) lays out a seven-stage programme for bringing national insurance more in line with income tax.
The headline recommendation is for NICs to be paid on an annual, cumulative and aggregate basis, instead of the current system where NI is calculated weekly or monthly.