Ice nucleating particles (INP) capable of nucleating ice crystals via immersion freezing at temperatures above approximately -35oC may strongly influence cloud glaciation, with implications for global precipitation and climate feedback. In addition to mineral and soil dust and marine organics, laboratory and field measurements suggest biomass-burning aerosols (BBA) can act as immersion-mode INP between around -30oC and -15oC. However, the contribution of BBA to the global INP budget remains poorly understood. Large uncertainties mainly stem from poor knowledge of which fuels yield INPs and global coverage of those fuel types. Further uncertainty arises from unknown size distributions of the particles that contain minerals that act as ice nucleants. However, with some understanding of these uncertainties from sensitivity studies, the relative importance of ice nucleation activity of BBA compared to, for example, mineral dust and marine organics, can be quantified. In this work, we investigate the potential global importance of BBA as INP using a global aerosol-climate model, specifically the UK Met Office Unified Model (UM). We evaluate the model using field campaigns over four different regions. We examine potential uncertainties in particle size and fuel type on BBA-based INP concentrations. Averaged over June-September, BBA INP accounts for more than half of annual average total INP in 7% of model grid cells with temperatures between -30oC and -20oC. Our simulations suggest INP concentrations from BBA may be at least as important as mineral dust and marine INP over large regions of the atmosphere in seasons when biomass burning is frequent.