With the help of VLBI 24-hour sessions it is possible to determine a large number of parameters, including station and source coordinates, the Earth orientation parameters and parameters modelling the atmospheric delays. Due to he limitation of observations of 1-hour single baseline sessions (Intensives) only a few parameters, such as clock offsets, zenith wet delays can be estimated in addition to the parameter of main interest which is the UT1-UTC arameter. Since the accuracy of any a priori information is crucial for the accuracy of UT1-UTC, great care has to be taken concerning their choice. For example, errors in the remaining Earth orientation parameters, namely polar motion and nutation, have an impact on the estimation of UT1-UTC. Furthermore, missing or incorrect modelling of the atmosphere loading effect or tropospheric gradients can compromise the station coordinates and further the measurement of UT1-UTC. In this study, we performed Monte-Carlo simulations for a global 10x10 degree grid consisting of artificial VGOS telescopes, where errors in the a priori polar motion dxp,dyp and nutation dX,dY as well as in the station coordinates in either North-South, East-West or Up-Down are introduced. Through this systematic approach, we were able to investigate the impact of erroneous a priori information on the UT1-UTC estimation. In general, we examine that erroneous station coordinates have a variable effect depending on the direction of the error as well as baseline length and orientation. For example, concerning an error in the station height fewer baselines are impacted, making it less crucial compared to the effect of the same error in North-South or East-West direction. In previous studies, theoretical results concerning an error in the a priori polar motion have been obtained by the analysis of the corresponding partial derivatives suggesting perfectly East-West oriented baselines to be less impacted. In this study, we show that it is not as simple as that and therefore, more sophisticated analyses are necessary to investigate the impact of erroneous a priori information on the UT1-UTC measurement.