A Single Source of Truth (SSoT) approach means that access to a multitude of rights and services is preconditioned by participation in one and only one digital ID database. Errors in that database percolate through the entire system and are usually hard to correct. If you are unable to access the database or are (erroneously) logged as ‘foreign’, the trickle-down effect for socio-economic and political participation is vast and difficult to correct. The risk is that SSoT-based digital ID systems will not only lock out already excluded populations but also expose and lock out vulnerable groups who were able to use some forms of legal identity to access rights and services on the margins of analogue systems. As Bronwen Manby (LSE), an expert on human rights and statelessness explained: “Identification is not fundamentally a technological problem.” This notion is shared by many experts in the field who see rushed digitalisation, without scrutinising the underlying identification mechanisms first, as one of the key threats in the push to provide legal identity for all. Second, the technology space providing digital solutions is itself problematic. It is filled by virtually unsupervised private sector vendors, has no defined normative structure, appropriate legal framework, centralised supervisory body and no civil society participation. At the same time, the capacity of governments to scrutinise and supervise identity ‘solutions’ offered by the private sector is weak. The risk is that without a comprehensive legal framework for and supervisory mechanisms to oversee the technology, poorly designed ID systems may and will (un)intentionally lock people out of civil participation and development programming, rendering them invisible to the government and leaving them behind. This is already happening on the ground, in Kenya, where civil society is leading a legal battle against the government over a controversial biometric database called the National Integrated Identity Management System (NIIMS). NIIMS is intended to become a Single Source of Truth about Kenyan citizens and NIIMs registration will be required to access universal healthcare, get a passport, register as a voter, apply for a driving licence, register a mobile phone number, pay taxes, open a bank account and more. But on the ground, communities warn that the system could have devastating effects on groups that have historically struggled to secure identity documents and be recognised as Kenyan citizens. There is even a risk that Kenyan citizens will be registered as foreigners if they cannot produce the required documentation to demonstrate citizenship and some have been turned away from the registration process altogether due to lack of documents. This shows that not every digital solution will generate a legal identity for those who did not previously have documents or it will produce a legal identity that is problematic and incomplete. 4 Should we celebrate, and replicate, Aadhaar? India’s Aadhaar platform is the largest SSoT, biometrics-based identification system in the world and has rapidly become the main prototype digital ‘solution’ to legal identity for other countries to emulate. Data from the 2019 ‘State of Aadhaar’ report by Dalberg and the Omidyar Network helps to unpack the impact Aadhaar is having in terms of inclusive development. The study shows that just 8% of the population remains without Aadhaar, but that some of the most marginalised populations had lower Aadhaar enrolment levels than others. In Assam, where a citizenship verification exercise has cast 2 million people’s legal identity into doubt, 90% of the population do not have Aadhaar. 30% of India’s homeless are also without Aadhaar. Since Aadhaar also functions as a SSoT, errors in the data may have a significant impact. 20% of people who tried to correct an error in their Aadhaar data were not able to do it. The report concludes that Aadhaar has supported inclusion, with 49% of people using Aadhaar to access one or more services for the very first time. Yet, 0.8% of people experienced exclusion due to Aadhaar-related reasons from a key welfare service which they had earlier received. More than half of all people who produced Aadhaar to get a SIM card or bank account, said their provider accepted only Aadhaar, even after the Supreme Court ruling indicating that Aadhaar is not mandatory. This and the belief among 65% of those included in the study that Aadhaar is required to access services, shows how a database of this kind can have greater influence on inclusion/exclusion from rights and benefits than it is officially deemed to have, leaving those without Aadhaar potentially more vulnerable.