<P> Estimating and measuring access to finance is relatively difficult because relevant data are not readily available . A lack of consistent cross-country data on the use of financial services has led to the use of the number of deposit and loan accounts as a simple measure of financial access, although this is an imperfect measure of financial access . </P> <P> Financial services may be provided by a variety of financial intermediaries that are part of the financial system . A distinction is made between formal and informal providers of financial services, which is based primarily on whether there is a legal infrastructure that provides recourse to lenders and protection to depositors . The following table gives an overview of this distinction by showing the segments of financial systems by degree of formality . </P> <Table> <Tr> <Th> Tier </Th> <Th> Definition </Th> <Th> Institutions </Th> <Th> Principal clients </Th> </Tr> <Tr> <Td> Formal banks </Td> <Td> Licensed by central bank </Td> <Td> Commercial & development banks </Td> <Td> Large businesses Government </Td> </Tr> <Tr> <Td> Specialized non-bank financial institutions (NBFIs) </Td> <Td> Rural banks Post Bank Savings & loan companies Deposit - taking microfinance banks </Td> <Td> Large rural enterprises Salaried workers Small & medium enterprises </Td> </Tr> <Tr> <Td> Semi-formal </Td> <Td> Legally registered, but not licensed as financial institution by central bank </Td> <Td> Credit unions Microfinance NGOs </Td> <Td> Microenterprises Entrepreneurial poor </Td> </Tr> <Tr> <Td> Informal </Td> <Td> Not legally registered at national level (though may belong to a registered association) </Td> <Td> Savings (susu) collectors Savings & credit associations, susu groups Moneylenders </Td> <Td> Self - employed Poor </Td> </Tr> </Table> <Tr> <Th> Tier </Th> <Th> Definition </Th> <Th> Institutions </Th> <Th> Principal clients </Th> </Tr>

Lack of access to financial services is technically known as