Highly polymer-modified binders (high PMBs) can increase the pavement service life, improve performance, reduce material consumption or increase recycled asphalt content in polymer-modified mixtures. However, currently criteria to classify high PMBs is lacking, thus limiting their application and causing challenges during quality control. Here we evaluated 10 different binders from two classes using conventional tests, multiple stress creep recovery (MSCR) test and binder fast characterisation test (BTSV). The results confirmed earlier reports that the softening point, elastic recovery and the Fraass breaking point do not allow to characterise polymer-modified binders confidently. The BTSV and MSCR tests provided more reliable means for discriminating binders based on polymer content. We, therefore, propose the use of the BTSV and/or MSCR tests for high PMB characterisation and offer preliminary criteria for discriminating between high PMB and conventional polymer-modified binders using each of the two tests.