The contact charge of styrene-co-butyl methacrylate powder containing a small fraction of a styrene-co-N-methylvinylpyridinium toluenesulfonate is found to depend on whether the nitrogen in the vinylpyridinium cation is ortho or para to the polymer chain. This is a particularly interesting result because the contact charge is proposed to develop from the transfer of the toluenesulfonate anion (OTs-) to the second surface, thus, giving it a negative charge while the powder develops a positive charge. The cation is not involved in the transfer, yet it clearly affects the mobility and transfer of the anion. These results are explained in terms of differences in ion aggregation in this highly nonpolar medium. © 1991, American Chemical Society. All rights reserved.