No matter an investor's age or financial starting point, it's never too late to start saving for retirement. One of the most powerful instruments available in the UK is the Stocks and Shares ISA, which offers tax-free returns and dividend income.

Please note that tax treatment depends on each client's individual circumstances and may be subject to change in the future. The content in this article is provided for information purposes only. It is not intended to be, and does not constitute, any form of tax advice. Readers are responsible for conducting their own due diligence and obtaining professional advice before making any investment decisions.

But having an ISA is just the start – and filling it with the right stocks is where long-term wealth is built.

Investment Strategy: Lessons from Buffett

Warren Buffett, one of the most successful investors in the world, has succeeded in turning just a few thousand dollars into a huge fortune. Today, his net worth is approaching $150 billion — proof that smart investing over decades pays off.

His approach still holds lessons: he invests within his “circle of competence,” and favors well-known, high-quality companies with wide moats — ones that can defend profits over time.

For ISA investors, the same principles apply. Choosing strong companies that you understand is more reliable than chasing fads. Regular monthly contributions allow the compound to do the heavy lifting, working its magic over time.

In the long term, it's not usually the big returns that matter most, but consistency, patience and strong fundamentals.

How does this apply to UK investors?

In the UK, well-established defensive stocks provide fertile ground for growth. Stocks in healthcare, consumer staples, utilities, or retail often provide stability during cycles.

among them, GlaxoSmithKline's (LSE:GSK) is a name worth considering for inclusion in a retirement-focused ISA. GSK operates in the pharmaceutical and vaccine space and is in the midst of revolutionizing its supply chain operations. By utilizing OMP's 'Unison Planning' enhanced Artificial Intelligence (AI) solutions, it aims to accelerate its Integrated Business Planning (IBP) capability.

This is just one example of how the company works to stay ahead of the competition.

However, drugs are vulnerable to regulatory changes, drug trial failures, patent declines, and intense competition. If major projects fail to materialize, this could undermine future growth prospects.

Finance and risks

Financially, GSK has shown strong performance in recent years, with strong margins and a high return on equity.

It consistently beats revenue and earnings expectations, and has paid its dividend reliably for more than two decades. The current yield is around 3.9%, which is moderate but sustainable thanks to healthy cash flow and dividend support.

The fact that GSK recently bought back its shares is encouraging — but buybacks alone can't hide weaknesses in R&D or product approvals.

I think an investor looking for a mix of income and growth might consider GSK a reasonable candidate for an ISA, especially with a long time frame and sufficient diversification.

Completion of pension

GSK is just one example of an established business with long-term potential. The real magic happens when a diverse mix of high quality stocks live within a stocks and shares ISA over many years.

Even starting at age 50, ongoing contributions can make a big difference. For example, £500 a month in a portfolio averaging 10% a year could grow to around £300,000 by age 68.

Such a sum, with a recommended withdrawal rate of 4%, could provide £1,000 a month on top of any pension.

So, while the path to retirement may seem daunting, combining the tax advantages of IMR with disciplined investment in high-quality businesses is a proven way to build lasting wealth.