Civil registration systems can provide data on marriages, by age and previous marital status of spouses, rank of marriage and other characteristics. They can also provide data on divorces, by age of spouses, length of marriage, number of dependent children and other characteristics.
Population registers can provide data on composition of population by marital status, sex and age.
Population censuses collect data on marital status by age and sex, usually defined in relation to the marriage laws or customs of the countries. Some censuses also collect data on duration of current marriage.
Household surveys routinely collect data on marital status. Some household surveys, especially family and fertility surveys and demographic and health surveys, may collect data on marital status in more detail, capturing not only marital status as defined by the marriage laws or customs of a country, but also various forms of informal unions such as consensual unions, cohabiting unions, or polygynous unions.
Demographic and health surveys and family and fertility surveys also collect data on age at first marriage/union, and duration of first marriage/union. Sometimes, data with regard to partnership history of individuals including all marriages and consensual unions may be also collected, such as in the Fertility and Family Surveys in Europe.