3. Registration and identification

A comprehensive system of taxpayer registration and identification is at the foundation of an effective tax system. It is the basis for supporting a range of tax administration activities such as self-assessment, value-added tax and withholding tax regimes, as well as third party reporting and matching. This chapter comments on several issues of significance in taxpayer registration and identification, including levels of registration, registration channels and identity management, and how the digital transformation affects these services.

The fundamental importance of an effective tax registration system cannot be overstated. These processes need to both manage those taxpayers that are “part of the system” and to help identify those yet to register. Furthermore, they need to be able to monitor and determine actions and interventions to establish any liability to tax for both individuals and corporate bodies, even in systems where filing is not mandatory.

Figure 3.1. provides information on the rate of registered personal taxpayers as a percentage of the total population. This shows a wide range of registration rates, often reflecting the level of integration the tax administration has with other parts of government.

While the majority of administrations are solely responsible for the system of registration for tax purposes within their jurisdictions, previous editions of this series have shown that in many jurisdictions the registration processes can also be initiated outside of the tax administration through other government agencies (OECD, 2019[1]).

In looking at how taxpayers can register, almost all administrations reported they provide more than one channel for taxpayers to use and 97% report that it is possible to register online (see Figure 3.2.). Compared to data from the 2017 edition of this series (OECD, 2017[2]) this is a 27-percentage point increase. Although in-person registration continues to be an important channel, or element of the registration process, often due to the need to provide physical evidence of identity, it is expected that as digital identity systems become more sophisticated, the dominance of online channels will grow.

While the underlying survey does not allow identification of whether the online registration channel is available for all tax types or taxpayer segments, jurisdictions report significant investment in digital identity programmes, including using artificial intelligence to improve efficiency and effectiveness. This is helping cement digital identity as the cornerstone of successful digital transformation activity, as the OECD Tax Administration 3.0 report (OECD, 2020[3]) identified. Indeed, in one jurisdiction (Saudi Arabia), taxpayers can only register online (see Tables A.74. and A.75.).

This shift to digital channels may also help drive further efficiencies, though as the shift to digital gathers pace further attention is being paid to those who may not have access to digital services. The example from Canada in Box 3.1. illustrates some of the work taking place to address this.

Given the pivotal role that registration and taxpayer identification play in underpinning the tax system, having up-to-date tax registers remains a high priority for most tax administrations. As past editions have shown, the large majority of administrations have formal programmes in place to improve the quality of the tax register (OECD, 2019[1]).

Therefore, it is unsurprising that other government bodies may wish to use the tax administration register for their own purposes to provide services to citizens or ensure compliance with laws and regulations. This is leading to the creation of cross government databases. As Figure 3.3. illustrates, 70% of administrations report the existence of a range of available databases.

Integration across government is increasing as governments see the potential in using information maintained by tax administrations, such as taxpayer address and bank information, to contact citizens and businesses or to make direct benefit or support payments (OECD, 2020[4]).

This is leading to closer collaboration between government agencies, and many of them are integrating (parts of) their IT systems to make tax registration part of other actions taxpayers undertake. For example, registering for tax at the same time as registering a company or registering the birth of a child; and/or to use the same identifier to allow taxpayers to access other government services.

All tax administrations, whether required to by law or as a matter of sound business practice, put considerable effort into ensuring the security of taxpayer information. In addition to internal processes to prevent unlawful attempts to obtain information and to ensure taxpayers’ rights are protected, all administrations have processes to ensure the person they are dealing with is in fact the taxpayer. Increasingly these approaches, which in many instances have now been extended to multi-step authentication, are making use of biometric information, unique to the taxpayer.

Tax administrations face similar challenges to other organisations in dealing with individuals or organisations that may misuse personal information to impersonate taxpayers in order to commit fraud. The on-going and, in many cases, organised nature of this activity is requiring administrations to devote considerable effort to the prevention of identity theft. Box 3.3. contains examples of the work tax administrations are doing in this respect.

Once the domain of multi-national businesses and those involved in international trade, small and medium-sized enterprises and individual taxpayers are now increasingly earning income sourced outside their jurisdiction of residence. As a result of the proliferation of online market-places and sharing and gig economy platforms, it is now easier than ever for example, to rent out holiday homes or sell goods abroad through online platforms.

Tax administrations are facing a raft of issues in supporting and responding to this growth in cross-border activity, including how they manage taxpayer information flows across borders. Previous editions of the tax administration series (OECD, 2019[1]) highlighted two international measures aimed at helping administrations to address these issues:

  • The European Union’s Electronic Identification Authentication and Trust Services (eIDAS) approach, which was introduced in 2014 and aims at increasing the confidence taxpayers and tax administrations can have in dealing with information flows and being able to manage identity and registration issues across borders.

  • The global standard on Automatic Exchange of Information (AEOI) – the Common Reporting Standard (CRS), which together with the United States Foreign Account Tax Compliance Act (FATCA) provides for the exchange of non-resident financial account information with the tax authorities in the account holders’ jurisdiction of tax residence.

Following the 2019 OECD report The Sharing and Gig Economy: Effective Taxation of Platform Sellers (OECD, 2019[5]), the OECD published in 2020 a set of Model Rules that set the framework for digital platforms to collect information on the income realised by those offering accommodation, transport and personal services through platforms and to report the information to tax authorities. A key objective for the Model Rules is to help taxpayers be compliant with their tax obligations, and to provide a consistent framework to help business provide information to tax authorities. This supports the Model Rules goal of streamlining reporting regimes for tax administrations and platform operators alike. (OECD, 2020[6])

Around the same time, the OECD Tax Administration 3.0 report (OECD, 2020[3]) identified the seamless taxation of platform sellers as a key action for multilateral collaboration. Work is currently ongoing to explore how co-operation between administrations and platforms can be deepened to explore the integration of identification and reporting processes into the applications used by the platforms in order to support tax compliance by platform sellers as well as reducing burdens for all parties.

More generally, common approaches to digital identity that are shared across government, and between government and third parties, will increasingly allow new services to be developed. These services can reduce burdens on taxpayers as third parties can supply information direct to tax administrations, as well as providing richer and more accurate pools of data to tax administrations.


[6] OECD (2020), Model Rules for Reporting by Platform Operators with respect to Sellers in the Sharing and Gig Economy, OECD, Paris, http://www.oecd.org/tax/exchange-of-tax-information/model-rules-for-reporting-by-platform-operators-with-respect-to-sellers-in-the-sharing-and-gig-economy.htm (accessed on 22 May 2023).

[3] OECD (2020), Tax Administration 3.0: The Digital Transformation of Tax Administration, https://www.oecd.org/tax/forum-on-tax-administration/publications-and-products/tax-administration-3-0-the-digital-transformation-of-tax-administration.htm (accessed on 22 May 2023).

[4] OECD (2020), “Tax administration responses to COVID-19: Assisting wider government”, OECD Policy Responses to Coronavirus (COVID-19), OECD Publishing, Paris, https://doi.org/10.1787/0dc51664-en.

[1] OECD (2019), Tax Administration 2019: Comparative Information on OECD and other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/74d162b6-en.

[5] OECD (2019), The Sharing and Gig Economy: Effective Taxation of Platform Sellers : Forum on Tax Administration, OECD Publishing, Paris, https://doi.org/10.1787/574b61f8-en.

[2] OECD (2017), Tax Administration 2017: Comparative Information on OECD and Other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/tax_admin-2017-en.

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