Fast pyrolysis of woody biomass is close to full maturity, with first-of-its-kind commercial size installations for fuel production being commissioned in Finland (Fortum) and in The Netherlands (Empyro), and in the design phase in Brazil (Ensyn). In the industrial-scale combustion tests, the use of fast pyrolysis bio-oil (FPBO) has been demonstrated to be a viable option to replace heavy fuel oil in district heating applications. Commercially usable district heating boilers and burners suitable for FPBO are available. There is research on diesel-engine and gas-turbine applications but, so far, no proven demonstrations. FPBO is completely different from mineral oils; hence, standards are needed. Analytical methods have been systematically validated and modifications to the standards as well as completely new methods have been made. Two ASTM burner fuel standards already exist and European boiler fuel grades are being developed under CEN. The focus on CEN standardization is on boiler use, because of its commercial readiness.