Central America has been the focus of many recent seismic risk studies, carried out for both public and private purposes. Public risk assessments are usually carried out for risk mitigation purposes so that the public are informed of the risk, building codes can be improved and emergency plans can be made.  Private risk assessments carried out by the (re)insurance industry look at only a subset of buildings (the insured or insurable mix) in order to derive adequate pricing for insurance contracts. Even if the end use is different, the two assessments share many similarities. For example, the seismic hazard component can be identical for the two assessments. In this study, we carried out a seismic risk assessment for Central America, focussing on Guatemala, using the publically available OpenQuake model (Global Earthquake Model) and a privately-licenced vendor catastrophe model. Our objectives were twofold; first, to gain a good understanding of the  similarities and the differences between the two models, and second,  to quantify the uncertainty of intermediate model components and their contribution to the overall risk estimation. The uncertainty in the risk calculation can indubitably affect the quality and the value of the risk assessment. A model with open architecture, such as OpenQuake, allows the investigation of primary and secondary uncertainty. Our approach to quantify the uncertainties within OpenQuake is also presented. The outcome of this study has shown that the most significant impact of uncertainty, both epistemic and aleatory, comes from the hazard component. Therefore, this presentation also aims to initiate a dialogue with the seismological community about the main contributors of hazard uncertainty in risk assessment. The contributors include, but are not limited to: 1. Seismic catalogue-seismic zonation 2. Selection of GMPEs 3. Soil model