International prefix meaning

The digits a caller dials before the country code to place an outgoing international call from the UK or Ireland. In practice, it is entered after accessing a public telephone network (fixed, VoIP or mobile, historically the PSTN) and before the destination country code and national number. It is commonly called the international access code or international dialling prefix. Across England & Wales, Scotland, Northern Ireland and Ireland the international prefix is 00. This is specified in Ofcom’s National Telephone Numbering Plan (UK) and ComReg’s National Numbering Conventions (Ireland) and aligns with ITU‑T E.164 recommendations. On mobile devices and in international number formats, the symbol “+” functions as a substitute for 00, but “+” is not itself the national international prefix. The term is descriptive rather than a statutory definition, but it is used in telecoms regulation, contracts, consumer terms, and in call data records to denote routing and charging of outgoing international calls. Correct use affects call completion, tariffing and compliance with number presentation, fraud controls and call blocking policies. Usage is consistent across the UK and Ireland.