Extending the pioneering work of Rasche and Woolcock [6] the electromagnetic corrections to the pion nucleon scattering lengths have been calculated in a recent publication [42] with a relativistic two channel approach. The results for the correction to the shift measurement and the width measurement are =-(2.10.5)10 and =-(1.30.5)10, respectively. The uncertainty of 5 together with the error in the Panofsky ratio can be considered as the final accuracy the experiment should reach.