In 1999 Back led the sale of German Parcel to Royal Mail, subsequently rebranded as GLS.
[10] During his tenure, UK parcel volume growth reached a four-year peak in 2018 and Royal Mail's share of the UK parcel market grew to 53% by volume by March 2018, driven by winning business from online retailers.
[11] In its 2019 full-year results, a year into Back's tenure as CEO, Royal Mail announced a five-year turnaround plan focused on expanding the company's parcels business internationally, addressing the growth in online deliveries.
As part of the plan, Royal Mail pledged to invest a further £1.8 billion in its UK postal service.
[16] Back and his family live in an apartment overlooking Lake Zurich,[17] Switzerland, where they have been resident since 2007 and where he is legally domiciled.