A leading tax consultancy said the government should simplify the personal tax system which is says is "too complex".
Bishop Fleming pointed to findings by the Office of Tax Simplification that there were too many tax reliefs and allowances and recommended amalgamating some and presenting them in a clearer order, simplifying the process of calculating tax liability and exempting some sources of income for basic rate taxpayers.
Andrew Browne, head of tax at Bishop Fleming, said: "There are over 20 different personal tax allowances and reliefs available, even for a fairly straightforward tax computation. It is a spaghetti junction of a mess.
"In addition to the number of reliefs there are at least 14 potential tax rates, making it impossible for any taxpayer to understand what rate they are paying."
Mr Browne added that a more straightforward tax system would help ensure computers were capable of calculating correct tax liabilities, an issue HMRC has struggled with in recent years.
He said: "We are just a couple of years away from the tax system being digitised, yet the Revenue cannot even correctly digitise some key aspects and is instead asking for paper returns. It does not bode well for the future."
Rachael Griffin, tax and financial planning expert at Quilter, said: "Relics of the past are lingering in the tax system and when combined with additional rules have created something like Frankenstein’s monster.
"Instead of being a coherent well-oiled system the taxation of savings has had numerous bolt ons, which makes the whole thing confusing for the industry let alone consumers."
The OTS would like to see a personal tax roadmap introduced along similar lines to one proposed in the government’s Making Tax Digital plans, which is being introduced to make it easier for individuals and businesses to get their tax right.
But Catherine Robins, tax partner at Pinsent Masons, said: "There have been a lot of initiatives over the years, but I’d question how successful they have been. Simplifying the current system would need pretty radical steps, and with Brexit on the horizon, not to mention the move to digital, this is probably not the right time for such an overhaul.
"I’m sceptical about any attempts to change the tax system now. It would take an awful lot of planning and preparation to get it right and ensure no companies or individuals lost out."