It is challenging to develop a physically based compact model for an organic thin-film transistor (OTFT). Moreover, there is still a lack of a universal model that would cover the huge variety of materials and device structures available for stateof-the-art OTFTs. Different models of charge transport phenomenon in organic semiconductors are briefly explained, since such phenomenon constitutes the basis of a physically based compact model of an OTFT. An introduction to the basic principles dictated on compact models suitable for Computer Aided Design (CAD) simulators is stated. Six reported models are presented and analysed with an emphasis on their primary assumptions and applicability aspects. Furthermore, the selected compact models are compared with experimental results provided by a fabricated OTFT. Finally, the authors conclude recommendations for advancing OTFT compact modelling in order to reach a more enhanced model that could characterise most recently reported OTFTs.