The European Green Deal targets to limit emissions by applying sustainable and greener technologies in transport, including last-mile delivery services. The aim is to estimate the potential impact of application of greener last-mile delivery technologies in the companies on sectoral and regional development in Latvia, using the input-output approach applying the latest data set of 2020 for Latvia. The economy is disaggregated according to the NACE 2-digit level into 64 economic activities and regional development additionally into 5 regions (Riga, Vidzeme, Kurzeme, Zemgale, and Latgale). The bottom-up approach is used. According to NACE, postal and courier services (H53) are selected as the main focus in the research reflecting last-mile delivery services. Sweden is used as a benchmark country as Sweden is already having one of the greenest transport sectors. Modelling results argue that if the postal and courier services in Latvia apply a greener technology that already exists (possible, achievable technology, not just in theory), then the total value added declines by -0.1% due to lower intermediate consumption for manufactured products. The most positive impact is on services (as warehouse services, employment services, wholesale trade services), however, the services auxiliary to financial services and insurance services, air transport services, paper and its products have the most negative impact. The modelled regional results claim that the major negative impact is in the metropolitan areas (Riga region), medium - Kurzeme and Latgale, minimal impact - Vidzeme and Zemgale. The findings are valuable to the companies in the industries that might be affected due to the shift towards other technologies and practices, as well as for the national government and EU institutions in policymaking.