Natural History institutes hold an immense number of specimens and artefacts. For years these collections were not accessible online, remaining inaccessible to researchers from far away and hidden from the general public. Large digitisation projects and cross-institutional agreements aim to bring their collections into the digital era, such as the SYNTHESYS+ project and the Distributed System of Scientific Collections (DiSSCo) Research Infrastructure. As specimens are 3D physical objects with different characteristics many techniques are available to 3D digitise them. For inexperienced users this can be quite overwhelming. Which techniques are already well tested in other institutions and are suitable for a specific specimen or collection? To investigate this, we have set up a dichotomous identification key for digitisation techniques: DIGIT-KEY, (https://digit.naturalheritage.be/digit-key). For each technique, examples used in SYNTHESYS+ Institutions are visualised and training manuals provided. All information can be easily updated and representatives can be contacted if necessary to request more information about a certain technique. This key can be helpful to achieve comparable results across institutions when digitising collections on demand in future DiSSCo research initiatives coordinated through the European Loans and Visits System (ELViS) for Virtual and Transnational Access.