Message event
A message being received or sent. The message event is an event circle with an envelope inside: an unfilled envelope waits for a message, a filled one sends it.
Easily confused with
How to read it
The envelope can go in a Start event (the process starts when a message arrives), an Intermediate event or an End event. BPMN 2.0.2 requires the marker to be filled when the event throws (sends) a message and unfilled when it catches (receives) one. A message in BPMN is more than a letter: Camunda’s BPMN reference says the meaning is not restricted to letters, e-mails or calls, and Politecnico di Milano’s exercise book describes it as any exchange with the outside, of data or material, with a participant in another pool.
Also searched as: bpmn message, bpmn message event, envelope bpmn, message event symbol.
Look-alikes
A Timer event has a clock in the same circle. The dashed arrow between pools is a message flow, the line a message travels along; the envelope event is the point where it is sent or received. In a UML sequence diagram a message is an arrow between two lifelines.
Read next
- Next in BPMN symbolsTimer eventA point where a process waits for a time or date, or starts on a schedule. The timer event is an event circle with a clock face inside.
- The same shape in African flagsFlag of the African UnionThe African Union’s flag shows a map of Africa on a green field, surrounded by rays of light and a ring of stars. The African Union says the stars, 55 of them, represent its 55 member states; the Assembly’s 2007 decision asked for a green background to symbolise Africa’s hope.
More BPMN symbols
The same shape elsewhere
Browse symbols drawn with circles or squares and rectangles.
Sources
- Business Process Model and Notation (BPMN), Version 2.0.2, OMG document formal/2013-12-09, December 2013 (also ISO/IEC 19510), Object Management Group, Section 10.5.4, Table 10.89 and Section 10.5.2
- Business Process Modeling Notation (BPMN): Modeling Exercises, Cinzia Cappiello, Pierluigi Plebani and Monica Vitali, v.1.1, 2016 (CC BY-SA), Politecnico di Milano, Chapter 3, 3.1 and 3.2
- BPMN 2.0 Symbols: a complete guide with examples, BPMN reference, adapted from Freund and Rücker, Real-Life BPMN, Camunda, Events: Message
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
Added .