Double taxation traditionally occurs when a taxpayer is taxed twice on the same income by two jurisdictions (source jurisdiction & residence jurisdiction). Relief is usually made on a unilateral basis (domestic laws) or a bilateral basis (DTAs). HKSAR is actively establishing a network of comprehensive DTAs with its major trading and investment partners (over 20 agreements have been reached – not all are in force). Where no comprehensive DTAs exist HKSAR has over 25 agreements for avoidance of double taxation on airline income, 6 on shipping income (plus 2 agreements combining two areas). HKSAR is a destination for trade and investment, and seen as an attractive entry for many countries into the wider South East Asian economies. Also HKSARNZ Free Trade Agreement. HKSAR is mounting a serious challenge to Singapore (with over 60 DTAs), as a location to locate holding companies.