Over 1.1 billion people mainly in Asia and Africa lack official proof of identity that would get them access to public health care, education and finance, according to the World Bank.
More than a third of these "invisible" people are children, the Bank said in a report issued for its annual meeting in Washington this week.
That is particularly hard on groups of people forcibly displaced by unrest and disasters.
To address the problem, the World Bank has launched its ID4D program to expand digital identification programs in ways that can help fight poverty.
The poverty-fighting institution has digital identification and civil registration projects worth more than $500 million in more than a dozen countries.
It says such programs can also help governments decrease waste and boost innovation in delivering crucial services.
"We are at an exciting point of technology, collaboration and commitment converging to make unprecedented improvements in the lives of the 1.1 billion people living without identification," said World Bank Group Chief Executive Kristalina Georgieva.
ID4D advisory council member Eric Jing, CEO of China's AliBaba group payment unit Ant Financial, added that "families are left without access to health care, education and social and financial services."