- Since 2013 in the business of travel management.
- Background is in Book-Keeping and Accounting.
- It all started as In-house guide at Canterbury Cathedral in 2012.
- Green Badge City guide for Canterbury in 2014.
- Tour Management in the South East of England since 2014.
- Blue Badge Tourist Guide for the South East of England in 2017.
- Blue Badge Tourist Guide for the South West of England since 2018.
- Lowland Walking Leader since 2019.
- member of the Guild of Tourist Guides – https://britainsbestguides.org/guides/kerstin-muller/
- member if the Institute of Tourist Guiding – https://www.itg.org.uk/our-guides/
- member of SEETGA – http://southeastbestguides.org/visit-south-east-england-professional-tourist-guides/deutsch/
- member of AWCTG – https://awctg.co.uk/blue-badge-guides/other-areas/104-kerstin-muller-tourist-guide