The Stocks & Shares ISA
The Stocks & Shares ISA is the simplest of the three to think about. You can put up to GBP 20,000 a year (2026/27 allowance) into one. Inside the wrapper, you pay no UK capital gains tax on growth and no UK income tax on dividends or interest. When you take money out, you take it out tax-free. There is no minimum holding period and no penalty for withdrawing early.
Two caveats. First, the ISA allowance is per person per tax year, not per account, so opening five ISAs does not give you GBP 100,000 of headroom. Second, the wrapper protects against UK tax only - if you move country, you may lose the tax-free treatment depending on the destination's rules.
The SIPP
A Self-Invested Personal Pension is a UK pension wrapper you control yourself, in contrast to a workplace pension where the employer chooses the platform. The two big mechanical features are tax relief on contributions (basic rate added at source, higher rate reclaimed via self-assessment) and the 25% tax-free lump sum at retirement (currently capped at GBP 268,275 in absolute terms).
The trade-off is liquidity. Your money is locked up until age 57 from 2028 (rising from 55), which is the price you pay for the tax relief. SIPP contributions are also subject to the annual allowance (GBP 60,000 in 2026/27, tapered for high earners) and the lifetime allowance was abolished in 2024 but a new tax-free lump sum allowance applies.
The General Investment Account
A General Investment Account (GIA) is everything that is not an ISA, a SIPP or a similar wrapper. It is just a brokerage account. You can hold any amount; capital gains on disposals are taxable above the annual exempt amount (GBP 3,000 in 2026/27); dividends are taxed above the dividend allowance (GBP 500 in 2026/27).
The GIA is where money goes once the wrappers are full, or where wrapper-incompatible holdings live (some structured products, some non-UCITS funds, etc.). It is also the right home for short-term holdings you might need before retirement age and might fail to accommodate inside an ISA's annual cap.
The order most people should fill them
There is no universal right answer, but the most common-sense default for someone with no employer match and no immediate liquidity need is: ISA first up to your annual cap, SIPP second up to whatever you can tolerate locking until retirement, GIA last for anything left over. The reason is that the ISA is uniquely flexible - tax-free, no age gate, no liquidity penalty - and the SIPP gives strictly more after-tax return than the GIA but with the lock-up.
There are real exceptions. If your employer matches pension contributions, the SIPP-equivalent (workplace pension) goes first because the match is free money. If you are a higher-rate taxpayer who expects to be a basic-rate retiree, the SIPP is more attractive than the ISA on the maths because you get 40% relief in and pay 20% on most of the way out. If you need the money before age 57, the GIA wins regardless of the tax cost, because the wrapper liquidity penalty exceeds the tax saving.
Where seeing them together helps
Once you have ISA, SIPP and GIA holdings spread across two or three brokers, the wrapper view is what stops you double-counting. A FTSE 100 tracker held inside an ISA at Hargreaves Lansdown and a similar tracker inside a Trading 212 GIA can quietly leave you 15% over your intended UK-equity allocation if you only look at each platform in isolation.
This is one of the things a multi-broker portfolio dashboard earns its keep on. Bank AI surfaces the wrapper as first-class metadata on every holding (ISA, SIPP, GIA, plus the EU equivalents) so allocation is reasoned across wrappers, not within them.
Frequently asked questions
Can I have an ISA at more than one provider?
Yes. From the 2024/25 tax year, you can open and contribute to multiple Stocks & Shares ISAs in the same tax year, as long as the total contributions across them do not exceed the GBP 20,000 annual cap. The previous restriction (one provider per tax year per ISA type) was abolished.
Can I move money between an ISA, a SIPP and a GIA?
Within an ISA you can transfer between providers without losing the wrapper. Between an ISA and a SIPP, no - they are separate regimes. You can move money out of an ISA and into a SIPP, but the contribution counts against the SIPP allowance. From a GIA into an ISA you can do a 'Bed & ISA' to use your annual ISA allowance, but capital gains are still realised on disposal.