In this paper, a new analytical method is presented that can be used to determine the behavior of a particular steel beam-to-column extENDed END PLATE connection in linear and nonlinear regions. A common means of forming a rigid joint between a universal beam and column is to weld an END PLATE to the beam END and then to bolt it to the column. A physically based analytical method that can predict the behavior of bolted and extENDed END PLATE eave connections, using the connection dimensions as input, is presented. This article demonstrates an analytical procedure for the establishment of elastic and plastic parts of the M-q curve of this form of connection. An analytical method is proposed for the extENDed END PLATE joints having four bolts in the tension region and without any stiffened PLATE. However, the presented technique can also properly be extENDed to other types of this form of connection. An extensive approach to estimate the plastic stiffness of the connection has also been performed. Comparison is made on a series of test results for a range of bolted END PLATE moment connections and good agreement is achieved. Furthermore, the authors believe that the method presented shall efficiently serve design engineers in real design conditions.