The Scottish Government's Fiscal Commission Working Group believes independence would allow unnecessary complexities built up in the UK tax system over centuries to be swept away.
The move would make tax collection more efficient, the group says.
Proposals for an independent Scotland's tax system will be set out in a report from the Fiscal Commission Working Group in the next few days.
It will highlight the UK's £32 billion "tax gap" of uncollected revenues and the estimated 10,000 pages of current tax legislation.
Expert group chairman Crawford Beveridge said: "It is undisputed that there is significant room for improvement in the UK tax system that Scotland would inherit.
"Over many years, the accretion of increasingly complicated provisions has left a system which is complex and lacking a clear set of guiding principles."
The report will accuse successive UK Governments of failing to make the "substantial reforms" called for in a series of previous reviews.
The comments suggest the Scottish Government is preparing for a more radical overhaul of the tax system than of the welfare state, in the event of independence.
In June, ministers backed calls for an independent Scotland to share the UK's welfare system, at least for a transitional period. In a report, the Scottish Government's expert group on welfare warned of "serious risks" to payments if an independent Scotland created a stand-alone system immediately.
The Scottish Government is already creating its own tax agency, Revenue Scotland, to collect taxes on property transactions and landfill, which are due to be devolved next year.
The Fiscal Commission Working Group - which last week backed the creation of an oil fund - will also recommend creating a permanent fiscal commission for an independent Scotland, equivalent to the UK's Office for Budget Responsibility. The body would provide independent economic assessments and forecasts.
Speaking ahead of the reports, Finance Secretary John Swinney said: "We are already introducing two reformed taxes in Scotland that will be cheaper to collect, more progressive for individuals and tailored to Scotland's needs and have proposed a General Anti-Avoidance Rule to ensure we crack down on anyone trying to dodge their taxes.
"With independence we have opportunities to use taxation to make Scotland wealthier and fairer and to improve the tax system overall."