When mortgage rates are falling and savings accounts yield 3%, if lucky, the appeal of dividend shares is impossible to ignore. The FTSE 100‘s average 3.4% yield looks attractive on paper, and some names — such as Legal & General at 8.1% — seem to offer mouth-watering returns.

Yet this income temptation masks five critical dangers that could leave portfolios at risk if investors aren’t careful.

Dangerous concentration

The Footsie’s dividend income is alarmingly concentrated. The top five dividend payers account for 28.7% of total dividend payments, while the wider top 15 companies represent almost 60% of the index’s income.

This creates a structural vulnerability: the FTSE fell 30% during Covid but dividend payments fell only 10%. But if those concentrated payers face earnings pressure simultaneously, the cuts could be far more severe.

The life insurance time bomb

Life insurers dominate the high-yield space, with Legal & General and Phoenix Group offering 8.1% and 7.9% respectively. This concentration in one sector amplifies risk. With interest rates now expected to reach 3% by year-end, margins will be squeezed on the billions these firms manage.

The paradox: falling rates that make dividends more attractive are simultaneously eroding the earnings that support them.

Housebuilder cyclicality

Taylor Wimpey yields 9.2%, but the yield hides underlying issues. The sector also faces margin pressure from build-cost inflation, uncertain demand recovery and regulatory risk around supply reforms and tax policy. If completions slow or costs spike, dividends become vulnerable — regardless of current policy changes.

Dividend cover deteriorating

Many high-yielders currently struggle with dividend cover. Land Securities (LSE:LAND) illustrates the challenge acutely. The company’s payout ratio stands at 167%, meaning it’s distributing significantly more cash to shareholders than it generates in current earnings. However, critically, it also demonstrates why this situation may be temporary rather than terminal.

A case study in dividend recovery

With a £9.3bn valuation, Landsec owns and manages premium commercial and residential property in the UK. Trading at around 650p, it offers a dividend yield of 6.5%. The company’s become increasingly attractive to income investors seeking exposure to London’s property market recovery — and recent management updates suggest the recovery narrative has genuine foundation.

Still, it faces notable challenges. With a payout ratio of 167%, the company’s returning more than current earnings to shareholders. This is only sustainable if earnings growth accelerates meaningfully. And with £4.65bn in total debt against only £424m in EBITDA, there’s a risk it may have to cut dividends if earnings don’t improve.

Encouragingly, the latest half-year results suggest management’s executing a credible turnaround. The company sold £644m of low-returning assets, with a further £1bn planned over the next three years, redirecting capital into higher-yielding assets. And it looks like it’s already working, with like-for-like rental income growing 5.2% in H1 2025, with office occupancy reaching 98.8% and retail occupancy at 96.7%.

Also, shopping centre trading in the final Golden Quarter revealed market-beating sales.

The bottom line

High dividend yields aren’t free money — they’re compensating investors for risk. Before buying dividend shares, always check dividend cover, debt, sector vulnerability and operational proficiency.

Landsec offers potential for a meaningful turnaround, but it requires patience and conviction that management can deliver on its strategy. As always, there’s moderate risk.

Still, I think it’s one of the more promising dividend shares to consider this year.