Building a sustainable and growing second income through investing doesn’t require extraordinary skills or insider knowledge. Private investors have one powerful ally: time. With a long-term approach, even modest amounts can grow into a significant stream of passive income.

Here’s how an investor can start with just £2,000 (or even less).

Take advantage of the power of FTSE 100 stocks

The FTSE100 the index is a fantastic source of income. Over the long term, investing in a diversified selection of UK blue chip stocks can build wealth through a combination of dividends and share price growth.

While even gigantic UK companies can be volatile in the compact term, history shows that over time shares outperform most other asset classes. A good starting point is a well-constructed portfolio of 15-20 FTSE 100 shares. Targeting reliable, established companies with a robust customer base and consistent dividend growth is key.

These companies are often better prepared to weather economic turmoil while rewarding shareholders with regular payouts.

Cigarette manufacturer Imperial Brands (LSE: IMB) is a good example for investors to consider. Despite tobacco controversy and ongoing regulatory challenges, it has shown it has the strength to adapt and survive. Management has worked difficult to build robust brands, maintain market share and transition to next-generation products such as heated tobacco and vaporization devices.

Investors prefer Imperial Brands for its reliable source of dividend income. Today, the final yield is an impressive 5.8%. This is well above the FTSE 100 average of 3.5%. However, this is not guaranteed. There is no dividend.

Imperial Brands’ share price has also been rising recently. Last year it increased by 38%.

Stocks are on fire!

After a good run, there’s a good chance the stock will remain idle. There are long-term risks. Restricting vaping could wreak havoc and the number of people smoking could continue to decline. However, over the years, Imperial Brand has shown resilience. Personally, I don’t buy tobacco stocks, but I think investors who do should consider it an excellent source of dividends and maybe some share price appreciation.

Long-term investing requires patience and harnessing the power of compounding. Over the last 20 years, the FTSE 100 has delivered an average annual return of 6.9%, including reinvested dividends.

Let’s assume a 25-year-old investor saves £2,000 and leaves it in the market for 40 years. With this average return, their investment would have grown to £28,850 by the age of 65. A rate of return of 5.8% would provide a second income of £1,673 per year. Not bad for a £2,000 investment.

However, investing is not a one-time process. Let’s assume the same investor saved £2,000 every year for 40 years, using the same growth assumptions. Their portfolio would have increased to £415,973 by the age of 65. Paying out 5.8% per annum would generate an annual income of £24,126. This is an excellent return, although inflation in real terms will reduce purchasing power.

While the stock market offers compelling growth potential, there is no risk-free investment. Market returns may be lower than expected and individual companies may face challenges. Diversification is key to limiting the impact of individual underperforming stocks.

Although £2,000 a year is a solid sum, by gradually increasing it over time our investor can generate even more impressive rewards.