All businesses, whatever their size, must understand how they’re affected by competition law. You must follow the rules on all types of anti-competitive activity.
You must follow rules on data protection if your business stores or uses personal information. This applies to information kept on staff, customers and account holders.
The law on selling your services door-to-door. n.b. Exceptions – These rules don’t apply to goods and services worth £42 or less.
Link to Governmental Site for window cleaners in Scotland. https://www.gov.uk/window-cleaners-licence-scotland