At Vienna University of Technology, the so-called balance method (BM) was developed to determine fossil and biogenic CO(2) emissions from waste-to-energy (WTE) plants. Meanwhile, the BM has been routinely applied to several WTE plants for some years, providing a large set of data. The average site-specific emission factors for fossil CO(2) were found to be in the range of 260- 780 kg CO(2) t(-1) waste, and 30-67 kg CO(2) GJ(-1) energy of the waste incinerated. These values are significantly different from the values that are found in the literature. Our results show that there is no such typical emission factor for WTE which could be applied to national CO(2) measurements or accurate emission trading. This study reveals that instead of generic emission factors the BM can be used as a standard for WTE plants, since its application requires either no or only a few additional installations.