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How to Review Your ISA Performance Each Year

Analyst Team trader
Updated 5 Dec 2025

Regular ISA performance reviews are essential for maintaining a healthy investment portfolio and ensuring your savings remain aligned with your long-term financial goals. Many investors spend considerable time selecting new investments each year but neglect to evaluate their existing holdings, which can lead to unbalanced portfolios and missed opportunities.

An Individual Savings Account (ISA) offers tax-efficient investing, allowing you to hold various assets without paying tax on interest, dividends, or capital gains. However, despite these benefits, ISAs are not always used to their full potential. Both new and experienced investors can fall into common ISA mistakes that limit the effectiveness of their ISA strategy.

Conducting an annual ISA performance review ensures your investments remain diversified, cost-effective, and suitable for your current circumstances. This systematic approach helps identify underperforming assets, rebalance allocations, and optimize your investment strategy for the year ahead.

Why Annual ISA Reviews Matter

Portfolio reviews force you to confront both successes and failures in your investment decisions. This process may feel uncomfortable, particularly when reflecting on past mistakes or considering whether to sell winning investments that have become overvalued. However, this discipline is crucial for long-term investment success.

Markets are cyclical, and different sectors experience periods of outperformance and decline. Without regular reviews, your portfolio may become concentrated in specific areas, exposing you to unnecessary risk. For example, technology stocks have performed well in recent years, but investors who failed to rebalance their holdings may find themselves overexposed to this single sector.

The importance of maintaining diversification cannot be overstated. Modern Portfolio Theory, developed by economist Harry Markowitz, demonstrates that portfolio characteristics should not be viewed in isolation but rather for their impact on overall risk and return. A well-diversified portfolio can achieve better risk-adjusted returns than the sum of its individual components.

Compare to Benchmarks

Benchmark comparison forms the foundation of effective ISA performance evaluation. This process involves measuring your portfolio's returns against relevant market indices to determine whether your investments are delivering competitive performance.

Start by identifying appropriate benchmarks for your holdings. For UK equity investments, the FTSE 100 or FTSE All-Share indices provide suitable comparisons. Global equity portfolios should be measured against the MSCI World Index, while bond investments can be compared to the Bloomberg UK Aggregate Bond Index.

Calculate your portfolio's total return over the review period, including both capital gains and dividend income. Compare this figure to your chosen benchmark's performance over the same timeframe. Remember that benchmark comparison should account for the risk level of your investments – higher-risk portfolios should be expected to outperform lower-risk benchmarks over time.

Consider both absolute and risk-adjusted performance metrics. While your portfolio may have generated positive returns, it may have underperformed relative to the additional risk taken. Use metrics such as the Sharpe ratio to evaluate whether your returns adequately compensate for the volatility experienced.

Document any significant performance gaps and investigate the underlying causes. Underperformance may result from poor stock selection, sector allocation decisions, or timing of investment decisions. This analysis provides valuable insights for future investment choices.

Review performance over multiple time periods to gain a comprehensive view. Short-term underperformance may be acceptable if long-term trends remain positive, but consistent underperformance across multiple periods may indicate the need for portfolio changes.

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Check Allocation

Asset allocation review ensures your portfolio maintains appropriate diversification and remains aligned with your risk tolerance and investment objectives. Over time, market movements can cause your allocation to drift from your target percentages, creating unintended risk exposures.

Begin by documenting your current asset allocation across major categories including UK equities, international equities, bonds, and alternative investments. Calculate the percentage weight of each category and compare these figures to your target allocation established at the beginning of the investment period.

Identify any significant deviations from your target allocation. If equity markets have performed well, your stock allocation may have increased beyond your intended level, requiring rebalancing to maintain your desired risk profile. Conversely, if certain asset classes have underperformed, you may need to increase allocations to maintain diversification.

Examine sector and geographic diversification within your equity holdings. Technology stocks, for instance, may have grown to represent a disproportionate share of your portfolio due to strong performance. While this concentration may have generated positive returns, it exposes your portfolio to sector-specific risks that could result in significant losses if technology stocks decline.

Review your international diversification to ensure adequate exposure to different geographic regions. Home bias – the tendency to overweight domestic investments – is common among UK investors but can limit portfolio diversification benefits. Consider whether your international allocation provides sufficient exposure to developed and emerging markets.

Assess the correlation between your holdings to identify potential concentration risks. Investments that tend to move in the same direction offer limited diversification benefits and may increase portfolio volatility during market downturns.

Evaluate whether your current allocation remains appropriate for your investment timeline and risk tolerance. Life circumstances change, and your portfolio allocation should evolve accordingly. Investors approaching retirement may need to reduce equity exposure and increase fixed-income allocations to preserve capital.

Consider rebalancing strategies to restore your target allocation. This process involves selling overweight positions and purchasing underweight assets, effectively implementing a disciplined approach of selling high and buying low. Regular rebalancing helps maintain portfolio diversification and can enhance long-term returns.

Review Fees

Fee analysis represents a critical component of ISA performance review, as investment costs directly impact your net returns over time. High fees can significantly erode investment performance, particularly when compounded over many years.

Start by identifying all fees associated with your ISA holdings. These may include annual management charges for funds, dealing fees for individual stock transactions, platform fees charged by your ISA provider, and exit fees for certain investments. Create a comprehensive list of all costs to understand the total expense burden on your portfolio.

Calculate the total expense ratio for your portfolio by weighing each holding's fees by its portfolio percentage. This figure represents the annual cost of maintaining your current investment mix and provides a baseline for comparison with alternative options.

Compare fund management fees across similar investments to identify potential savings opportunities. Active funds typically charge higher fees than passive index funds, but this additional cost should be justified by superior performance or other benefits. If actively managed funds consistently underperform their benchmarks after fees, consider switching to lower-cost alternatives.

Evaluate your ISA platform's fee structure to ensure it remains competitive. Platform fees vary significantly between providers, with some charging percentage-based fees while others use fixed annual charges. Calculate the total platform cost for your portfolio size and compare this to alternative providers offering similar services.

Review dealing fees if you trade individual stocks frequently. High transaction costs can quickly erode returns, particularly for smaller investment amounts. Consider whether your trading frequency justifies the associated costs or whether a different investment approach might be more cost-effective.

Examine any performance fees charged by your investments. These fees are typically levied when investments exceed certain performance thresholds but can be complex and expensive. Ensure you understand how performance fees are calculated and whether the potential benefits justify the additional costs.

Consider the tax efficiency of your holdings, as this impacts your after-tax returns. While ISAs provide tax shelter, the underlying investments' tax efficiency still matters for overall portfolio optimization. Funds that generate high levels of taxable income may be better suited to ISA wrappers than tax-efficient investments.

Investigate whether fee reductions are available through your current provider. Some platforms offer reduced fees for larger portfolio values or long-term customers. Contact your provider to discuss potential fee reductions or enhanced services at your current fee level.

Taking Action After Your Review

Once you have completed your comprehensive ISA review, develop an action plan to address any identified issues. Prioritize changes based on their potential impact on portfolio performance and the ease of implementation.

Create a rebalancing strategy if your asset allocation has drifted significantly from target levels. Consider the tax implications of any sales, though these are minimized within the ISA wrapper. Plan your rebalancing activities to minimize transaction costs while achieving your target allocation.

Research alternative investments if your current holdings are underperforming or charging excessive fees. Take time to evaluate potential replacements thoroughly, considering factors such as investment objectives, risk levels, fees, and historical performance.

Update your investment policy statement to reflect any changes in your circumstances or objectives. This document should outline your investment goals, risk tolerance, time horizon, and target asset allocation, providing a framework for future investment decisions.

Schedule your next review date to maintain regular portfolio monitoring. Annual reviews are typically sufficient for most investors, though more frequent monitoring may be appropriate during volatile market periods or significant life changes.

Consider seeking professional advice if your review reveals complex issues or if you lack confidence in making necessary changes. Financial advisors can provide valuable guidance on portfolio optimization, tax planning, and investment selection.

Document your review findings and decisions to create a record of your investment journey. This documentation helps track the effectiveness of your decisions over time and provides valuable insights for future reviews.

Regular ISA performance reviews are essential for maintaining an effective investment strategy. By systematically comparing performance to benchmarks, checking asset allocation, and reviewing fees, you can ensure your ISA continues to work effectively toward your financial goals. The annual review process may require time and effort, but the potential benefits to your long-term wealth accumulation make this investment in portfolio management worthwhile.

Remember that successful investing is a long-term endeavour requiring patience, discipline, and regular monitoring. Your annual ISA review provides the framework for maintaining these principles while adapting to changing market conditions and personal circumstances.

The AskTraders Analyst Team features experts in technical and fundamental analysis, as well as traders specializing in stocks, forex, and cryptocurrency.
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