To ensure an acceptable output beam quality, the performance of the RFQ has to be evaluated in presence of different sources of errors. Those errors include but are not limited to the RFQ machining, alignment and voltage errors, missteering and mismatch of the input beam. The effects of those errors on the beam quality can be rather large. For some of those errors tolerances can be specified only by running a large number of statistical simulations. The purpose of this document is to define tolerances on the considered errors from the beam dynamics point of view.