High-quality customs service Europe and the United States through the British customs"handcarry" service throughout customsCSS Courier Group... Since 1982...... International Courier and Express Freight.......... "It's The Connection That Connects" Welcome to an insight into CSS Courier Group, a name that is synonymous with quality, reliability and "peace of mind" within the international document and parcel industry.With our global network spanning 5 continents and delivering over 5,000 cities, there is nothing too difficult for CSS.