Both are ways to hold your investments with DMA. The main differences are tax and limits. A Stocks and Shares ISA shelters your investments from tax: no Capital Gains Tax on growth, no tax on dividends or income, and nothing to report on a self-assessment return. You can pay in up to £20,000 across your ISAs in each tax year. A General Investment Account (GIA) has no limit on how much you can invest, which makes it the natural home for money once your ISA allowance is used up. A GIA can also be held in joint names and is available to companies and trusts. Because it sits outside the ISA wrapper, Capital Gains Tax and tax on dividends and income may apply above your allowances, and you may need to report it. Both let you invest in shares, funds, ETFs and bonds, both accept transfers in from another provider, and neither has a fixed term — you can withdraw at any time.