The freezing of tax thresholds can result in a phenomenon commonly referred to as 'fiscal drag'. This occurs when tax allowances and rate bands remain unchanged while wages and inflation increase. As earnings rise, more taxpayers are ‘dragged’ into paying tax or moving to higher tax bands, despite there being no increase in the actual tax rates.

Fiscal drag is sometimes described as a “stealth tax” because government tax revenues increase without the need for headline rate rises. Its impact is particularly noticeable during periods of high inflation and wage growth, as pay increases intended to maintain living standards can instead lead to higher effective tax burdens.

The effect depends on several factors, including inflation, earnings growth and government policy regarding tax thresholds and allowances. Normally, thresholds may be increased annually in line with inflation, a process usually known as uprating. However, governments may decide to freeze thresholds for fiscal reasons.

In recent years we have seen a number of personal tax thresholds frozen for extended periods. As a result, increasing numbers of taxpayers are paying tax at higher rates, while some individuals who previously paid no Income Tax have become taxpayers for the first time. The Office for Budget Responsibility (OBR) estimates that the continued freeze in Income Tax thresholds until 2030-31 will raise more than £55 billion annually by 2030-31.

Fiscal drag can therefore have a significant impact on disposable income, particularly where salary increases are modest in real terms but still sufficient to move taxpayers into higher bands or reduce entitlement to certain allowances and benefits.