The use of mathematical modelling to inform and support tuberculosis (TB) policy-making has been encouraged by major funders and adopted by several high-burden countries. These quantitative planning exercises are undertaken to provide evidence for proposed interventions, improve the impact of TB funding and support funding applications. In recent years, a number of technical assistance providers have developed mathematical models and technical assistance capacity to support in-country TB policy decisions, and it is expected that the demand for technical assistance to support TB modelling will increase. The WHO Global Task Force on TB Impact Measurement provides global oversight to ensure that assessments of progress towards ending TB at global, regional and country levels are as rigorous, robust and consensus based as possible. The Task Force supports countries to improve the analysis and use of TB data for policy, planning and programmatic action, and is committed to the ongoing improvement of model-based policy analysis as a tool for strategic planning and budgeting. This document aims to provide concrete, pragmatic guidance for how TB modelling and related technical assistance is undertaken to support country decision-making. The target audience for this document are the participants and stakeholders in country-level TB modelling efforts, including the individuals who build and apply models; policy-makers, technical experts and other members of the TB community; international funding and technical partners; and individuals and organizations engaged in supporting TB policy-making.