Location Based Services (LBS) are meanwhile with all its variants a well established technology and also in the science a broadly discussed and described topic. Much of this is felt today as a "matter of course" and consumed daily at the always-ready mobile device. On more exact and critical consideration however it is to be noticed soon, that still a number of difficulties exist, for which, for most different reasons, no satisfactory solution can be found and implemented soon. This concerns in particular the core of each LBS, the determination of the place where the user accesses such a service. The accuracy respectively quality of such a localization decides finally, which LBS are possible, sensible and also economic. But definitely the description and assessment of the quality of these position fixings are a difficult and therefore mostly underestimated aspect of LBS. This of course does not apply equally to all services, with particular severity, however, to those, which are dependent on a meticulous and reliable localisation, as for example the mobile emergency call or in the future the (hopefully) EU-wide uniform and into vehicles integrated variant eCall. The present work argues exactly with this problem formulation. What factors, parameters, measures and regulations have been and are consulted in order to specify accuracies? Where do they work and where do they fail and what could be the reasons for it? Thereto, among other things, own measuring data and calculations from satellite fixes are used and discussed thoroughly. Finally some very determining statements can be made to the prerequisites, without which accuracies of localisations for LBS cannot be judged. Especially with mobile emergency services the accurate and reliable determination of their position is crucial for those seeking help, no matter where they are and with which methods this is carried out.