The IP Code (or International Protection Rating, sometimes also interpreted as Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures. The standard aims to provide users more detailed information than vague marketing terms such as waterproof.

The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. For example, an electrical socket rated IP22 is protected against insertion of fingers and will not be damaged or become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or 2X are typical minimum requirements for the design of electrical accessories for indoor use.

IP First number - Protection against solid objects
0 No special protection
1 Protected against solid objects over 50 mm, e.g. accidental touch by person's hands
2 Protected against solid objects over 12 mm, e.g. person's fingers
3 Protected against solid objects over 2.5 mm (tools and wires)
4 Protected against solid objects over 1 mm (tools, wires, and small wires)
5 Protected against dust limited ingress (no harmful deposit)
6 Totally protected against dust

IP Second number - Protection against liquids
0 No protection
1 Protection against vertically falling drops of water e.g. condensation
2 Protection against direct sprays of water up to 15o from the vertical
3 Protected against direct sprays of water up to 60o from the vertical
4 Protection against water sprayed from all directions - limited ingress permitted
5 Protected against low pressure jets of water from all directions - limited ingress
6 Protected against temporary flooding of water, e.g. for use on ship decks - limited ingress permitted
7 Protected against the effect of immersion between 15 cm and 1 m
8 Protects against long periods of immersion under pressure