ISA Returns on £30,000

Investing £30,000 in a UK ISA at 4.5% earns £7,385 tax-free over 5 years and £16,589 over 10 years. A basic rate taxpayer saves £469 in tax over 5 years compared to a standard savings account.

With £30,000 in ISAs, you earn £7,385 tax-free over 5 years at 4.5%. Note: the annual ISA allowance is £20,000, so you would need to build up this balance over 2 tax years. A basic rate taxpayer saves £469 in tax over 5 years, while a higher rate taxpayer saves £1,887.

ISA returns on £30,000 over time

The table below shows how £30,000 grows in an ISA at 4.5% versus a taxable account, for a basic rate (20%) and higher rate (40%) taxpayer.

Period	ISA value	ISA return	Non-ISA return (basic)	Tax saved (basic)	Tax saved (higher)
1 year	£31,350	£1,350	£1,280	£70	£340
3 years	£34,235	£4,235	£3,980	£245	£1,075
5 years	£37,385	£7,385	£6,878	£469	£1,887
10 years	£46,589	£16,589	£15,086	£1,271	£4,280

Returns assume compound growth at 4.5% per year. Non-ISA accounts deduct tax annually on interest above the PSA.

How the interest rate affects your ISA advantage

Higher rates mean more interest, more tax, and a bigger ISA advantage. Here is how £30,000 performs over 5 years at different rates (basic rate taxpayer):

Rate	ISA return	Non-ISA return	Tax saved
3.0%	£4,778	£4,776	£3
4.5%	£7,385	£6,878	£469
6.0%	£10,147	£9,026	£1,006
8.0%	£14,080	£12,046	£1,762

Building £30,000 in ISAs

The annual ISA allowance is £20,000, so reaching a £30,000 ISA balance takes at least 2 tax years of maximum contributions (excluding growth). Here is a suggested approach:

• Maximise each year — Contribute £20,000 before 5 April each tax year
• Invest early — Contributing at the start of the tax year gives more time for compound growth
• Consider your mix — Cash ISAs for short-term needs, Stocks & Shares ISAs for long-term growth
• Transfer old ISAs — You can transfer previous years' ISAs between providers without affecting this year's allowance

Compare ISA returns at other amounts

• £25,000: £6,155 tax-free over 5 years (£228 tax saved)
• £28,000: £6,893 tax-free over 5 years (£373 tax saved)
• £32,000: £7,878 tax-free over 5 years (£566 tax saved)
• £35,000: £8,616 tax-free over 5 years (£711 tax saved)

Frequently asked questions

How much will £30,000 earn in an ISA?

At 4.5%, £30,000 earns £7,385 tax-free over 5 years, growing to £37,385. Over 10 years, it grows to £46,589 (£16,589 return).

How much tax do I save with an ISA on £30,000?

Over 5 years at 4.5%, a basic rate taxpayer saves £469 and a higher rate taxpayer saves £1,887. Over 10 years, savings increase to £1,271 (basic) and £4,280 (higher).

Can I put £30,000 in an ISA in one year?

No. The annual ISA allowance is £20,000. You would need 2 tax years to shelter £30,000 in ISAs. However, you can transfer ISAs from previous years between providers without affecting your current allowance.

Cash ISA or Stocks & Shares ISA?

Cash ISAs are lower risk and suit savings you may need within 1–3 years. Stocks & Shares ISAs have higher potential returns over 5+ years but your capital is at risk. Many people use both — cash for near-term needs and investments for long-term growth.