1,000,000), local government will be administered by a metropolitan borough but the wider metro area may also have a county or regional combined authority.
However, as a regional administration its powers are limited, and the 32 boroughs plus the ancient City of London contained within it are responsible for the majority of services.
Areas outside any city's limit are considered to be unincorporated, and in most U.S. states they are by default regulated and taxed by the county.
In others, areas outside a city's limit fall within another type of local government, such as the civil township (a division of a county).
The distance this extends varies based on the population or area of the city, or which "class" it is considered to be under state law.
Home rule outside the city's limit is usually exercised by the county commission (which is often both legislative and executive), or the township's board of supervisors.
City limits or boundaries in California are regulated by Local Agency Formation Commissions (LAFCO).
City, town, and village limits are not usually coterminous with post office locations or ZIP codes, and the USPS even considers some places to be "unacceptable" for use on mail.