The gross tax gap is the difference between estimated ‘true’ tax liability for a given period and the amount of tax that is paid on time. As discussed below, it is important to note that the tax gap estimates cannot fully account for all types of evasion.
“These findings underscore the importance of ensuring fairness in our nation’s tax system,” said IRS Commissioner Chuck Rettig. “The increase in the tax gap estimates reflects that the IRS needs to do more, both in improving taxpayer service as well as working to improve tax compliance. The IRS remains committed to ensuring fairness and helping taxpayers while also working to better identify emerging compliance issues that contribute to the tax gap. The recent funding addition will help the IRS in many ways, increasing taxpayer education, significantly improving service to all taxpayers and focusing on high-income/high-wealth non-compliance in a fair and impartial manner supporting compliant taxpayers.”
After late payments and IRS efforts collected an additional $68 billion, the IRS estimated the net tax gap was $428 billion. This increase in the tax gap can be attributed to economic growth.
Between the two periods, 2011–2013 and 2014–2016, the estimated tax liability increased by more than 23 percent.
The tax gap estimates translate to about 85% of taxes paid voluntarily and on time, which is in line with recent levels. The new estimate is a slight improvement from 83.7 percent in a revised tax year 2011–2013 estimate, which dipped slightly from the original estimate released earlier. After IRS compliance efforts are taken into account, the estimated share of taxes eventually paid is 87% for 2014 – 2016.
The gross tax gap comprises three components:
- Nonfiling (tax not paid on time by those who do not file on time, $39 billion),
- Underreporting (tax understated on timely filed returns, $398 billion), and
- Underpayment (tax that was reported on time, but not paid on time, $59 billion).
A particular challenge for tax gap estimation is the time it takes to collect compliance data, especially data on underreporting that come from completed examinations (audits). To address this issue, the current release includes estimated tax gap projections for tax years 2017 – 2019.
Based on the projections for 2017–2019, the estimated average gross tax gap is projected to be $540 billion per year. The associated voluntary compliance rate is projected to be 85.1 percent. The projection of enforced and other late payments is $70 billion, which yields a net tax gap projection of $470 billion. The associated non-compliance rate projection is 87.0 percent.
The gross tax gap nonfiling, underreporting, and underpayment component projections for TaxYears 2017 – 2019 timeframe are $41 billion, $433 billion, and $66 billion respectively.
As part of the larger effort to reduce the actual tax gap, the IRS will continue to fairly enforce the tax laws. In 2021, the latest year for which data is available, the IRS currently collected more than $4 trillion in taxes, penalties, interest and user fees.
Tax gap studies through the years have consistently demonstrated that third-party reporting of income significantly raises voluntary compliance with the tax laws. And voluntary compliance rises even higher when income payments are also subject to withholding. The IRS also has an array of other taxpayer service programs aimed at supporting accurate tax filing and helping address the tax gap. These range from working with businesses and partner groups to a variety of education and outreach efforts.
The voluntary compliance rate of the U.S. tax system is vitally important for the nation. A one-percentage-point increase in voluntary compliance would bring in about $40 billion in additional tax receipts.
The tax gap estimates provide insight into the historical scale of tax compliance and to the persisting sources of low compliance.
The tax gap estimates provide insight into the historical scale of tax compliance and to the persisting sources of low compliance.
“Keeping the voluntary compliance rate as high as possible ensures that taxpayers believe our system is fair,” Rettig said. “The vast majority of taxpayers strive to pay what they owe on time. Those who do not pay their fair share ultimately shift the tax burden to those people who do, which fuels the tax gap. The IRS will continue to direct our resources to help educate taxpayers about the tax requirements under the law while also focusing on pursuing those who avoid their legal responsibilities.”
Estimating the tax gap; offshore, digital assets, other categories not fully represented. Given the complexity of the tax system and available data, no single approach can be used for estimating each component of the tax gap. Each approach is subject to measurement or nonsampling error; the component estimates that are based on samples are also subject to sampling error. For the individual income tax underreporting tax gap, Detection Controlled Estimation is used to adjust for measurement errors that results when some existing noncompliance is not detected during an audit. Other statistical techniques are used to control for bias in estimates based on operational audit data. Because multiple methods are used to estimate different subcomponents of the tax gap, no standard errors are reported. In addition, those reviewing this data should be mindful of these limitations when using these estimates.
Given available data, these are the best possible estimates of the tax gap components presented, although they do not represent the full extent of potential non-compliance. There are several factors to keep in mind.
- The estimates cannot fully represent noncompliance in some components of the tax system including offshore activities, issues involving digital assets and cryptocurrency as well as corporate income tax, income from flow-through entities, illegal activities because data are lacking.
- The tax gap associated with illegal activities has been outside the scope of tax gap estimation because the objective of government is to eliminate those activities, which would eliminate any associated tax.
- For noncompliance associated with digital assets and other emerging issues, it takes time to develop the expertise to uncover associated noncompliance and for examinations to be completed that can be used to measure the extent of that noncompliance.
The IRS continues to actively work on new methods for estimating and projecting the tax gap to better reflect changes in taxpayer behavior as they emerge.
