Effective tax rate
The share of pre-tax profit taken by tax according to the accounts — after reliefs, carried-forward losses and deferred amounts.
Formula
\text{Effective tax rate} = \frac{\text{Tax expense}}{\text{Profit before tax}}Stored as a fraction of one, not as a percentage. The numerator is the total tax expense from the income statement, including the deferred part.
How to read the number
Any gap against the statutory rate is explained in the notes, and the notes also show whether it is a one-off relief or a durable feature of the business.
When the metric lies
With a pre-tax loss the measure breaks down: the denominator is negative, and any value reads the opposite way.
Also known as: etr