There are three internationally standardized designations for minor planets, which are assigned by the Minor Planet Center (MPC). In order of assignment, these are:

For clarity and cross-referencing, it is usual for astronomical sources to identify a numbered object by both its permanent and provisional designations, or by its permanent designation (number) and name, at least in tables and for first mentions in a text.

Comets are also managed by the MPC, as are interstellar interlopers passing through the Solar System, but for them different cataloguing systems are used.

A provisional designation is automatically assigned when an object is reported to the Minor Planet Center (MPC), a branch of the International Astronomical Union, after at least two-nights observation. A permanent designation (sequential number) is assigned by the MPC once the orbital path is sufficiently secured for the object to be recoverable. A name is optional, and must be unique (the spelling must differ from all other asteroids when stripped of diacritics).

Over half of known minor planets have permanent designations/numbers. (See List of unnumbered minor planets.) Independent discoveries of an object may result in multiple provisional designations, but the requirement for a secure orbit means that the permanent designation is a unique identifier, apart from historical errors. In practice, a permanent designation can usually be assigned after the orbit has been secured by four well-observed oppositions. For near-Earth asteroids that have short orbital periods, one might be assigned after three or even two oppositions, whereas distant objects may require more. (2014 UZ224, for example, hasn't been assigned a permanent designation even after seven oppositions, as the uncertainty of its orbit is still large.)

Once a permanent designation has been assigned, the object is eligible for naming. The discoverer has the sole right to propose a name (subject to approval by the MPC) for ten years from the date it receives its permanent designation, after which time the option is open to the public (and to the MPC itself). The name must be unique: historically this only applied among minor planets (thus the asteroid 52 Europa and the Jovian moon Europa share a name), but since about 2005 names proposed for asteroids and moons have been rejected due to conflicts between them. Among the nearly a million minor planets that have been numbered, only about twenty six thousand (or 3%) have received a name; this percentage can be expected to decrease as the rate of discoveries accelerates.

In indexes and catalogues, compound designations are typically used for numbered objects. Thus the provisional designation alone will be used if the object is unnumbered, the number and provisional designation (or occasionally just the number) for numbered objects that have no name, and the number together with the name, or even all three designations, for named objects. This helps ensure that the object can be cross-referenced.

When the permanent designation/number is used alongside a second designation, the IAU and WGSBN present them thus: