Concurrent accreditation of an ambassador or high commissioner to two or more countries.
Termium website, [multiple accreditation](http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&index=alt&__index=alt&srchtxt=multiple+accreditation&comencsrch.x=5&comencsrch.y=5) (20.11.2014).
A head of mission may be accredited to more than one state, so long as the receiving states concerned have been duly notified and have raised no objection. Such multiple accreditation has often been found convenient for geographical reasons, or because it has been desired to limit expenditure on diplomatic missions. Subject to the same proviso, a member of the diplomatic staff of a mission may be similarly assigned to more than one state.
Based on New Zealand Ministry of Foreign Affairs & Trade, Glossary (7.11.2014).