Making pupils pay for public transport if they live less than three miles from school hurts attendance, head teachers have told inspectors.
These cost are a common reason for absence, secondary schools heads told an Estyn review - Estyn wants the three-mile rule to be looked at again.
Absence levels are significantly higher than before the pandemic, particularly among pupils from poorer backgrounds.
The Welsh government said affordable transport was one area being looked at.
Most children at secondary school are only eligible for free transport if they live three miles or more from the nearest suitable school.
School leaders told the inspectorate, Estyn, the policy contributes to non-attendance because pupils who are not eligible either face a long walk or have to pay for a return journey, which is often beyond the means of low-income families.
