With progressive digitization, modern production and with ever more complex measurements, measurement uncertainties and digital twins are becoming increasingly important. Metrological traceability is an important property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty. In every calibration, metrological traceability is an important consideration. Metrological traceability requires an established calibration hierarchy which could be shortened to a single step if the measurement is a direct fundamental physical realization of the measurement unit from its definition. With the SI unit definitions that have been valid since 2019, such measurements based on direct realizations are practically possible and are referred to as “one-step traceability” methods. After a short introduction into measurement uncertainties and metrological traceability we show different approaches for one-step traceability methods for the practical measurement of time, length, electrical units, mass, force and temperature.