Following in his father's and grandfather's footsteps, Peter applied for his license to become a certified mountain guide. After passing his examinations, he began as a porter in June and July 1914; he accompanied certified mountain guides and their clients as a porter to the summits of the Wetterhorn, Jungfrau, Mönch, Eiger, Finsteraarhorn, Faulberg, and the Gross Fiescherhorn over the great Aletschhorn. Charles Francis Alexander Fyfe, from Liverpool, England, wrote the first entry into Kaufmann's Führer-Buch: Peter Kaufmann was my porter, up to the top of the Wetterhorn today [June 22,1914], and I found him to be a safe companion of the mountain. J. V. I. Long, from Arundel, England, writes that Peter Kaufmann (nephew of Christian Kaufmann) . . . showed himself very capable and willing, carrying anything I asked him to without ever showing any sign of fatigue, even at the end of the climb, and I am convinced he will shortly make a first class guide.