Key messages ◼ The RUMINANT model qualifies as an advanced or “Tier 3” method for estimating emissions from enteric fermentation in ruminant livestock. ◼ The RUMINANT model was validated for enteric methane emissions from cattle in the tropical lowlands (Cauca Valley) of Colombia using six different diets given to feeder steers in 2017. ◼ There was a good correlation between field measurements of enteric fermentation using the polytunnel technique and estimates made using the RUMINANT model. ◼ Based on findings from the validation process, RUMINANT has been used to improve Colombia’s National Greenhouse Gas Inventory to the United Nations Framework Convention on Climate Change (UNFCCC) and the preparation of the sustainable bovine livestock Nationally Appropriate Mitigation Actions (NAMA) information note. ◼ The RUMINANT model could support the measurement, reporting and verification (MRV) phase of the NDCs of Colombia and other countries.