Fining parents for taking children out of school in term time in Wales has had no effect on overall absence rates, a review has found.
It shows the number of unauthorised family holidays actually increased after fixed penalty notices were introduced in 2013.
The review recommends changing the current system.
The Welsh Government, which commissioned the report, said it would consider the proposals put forward.
Cardiff saw the most fixed penalty notices issued in 2015-16 at 1,531, while Rhondda Cynon Taf (RCT) had 1,063 issued, 90% of which were fines for term-time holidays.
At the other end of the scale, Torfaen, Monmouthshire and Carmarthenshire councils issued no notices.
In Wales ministers have advised head teachers to use discretion to allow parents to take their children out of school for holidays, with fixed penalty notices being issued by councils to those who do so without permission from the school. But there are wide variations in policy of imposing fines in different council areas.
Meanwhile in England head teachers can allow term-time breaks in "exceptional circumstances" with parents facing the threat of being taken to court if they break the rules.
In Scotland fines are not issued but education authorities can issue "attendance orders" to make a parent explain a pupil's absence - if no reasonable excuse is given they can be taken to court.
In Northern Ireland no fines are issued, with children's attendance being monitored instead.
The report - which surveyed teachers and staff of local authorities and local education consortiums - found the biggest decline in overall absence was in the two years before the Welsh Government brought in the fines.
Several respondents said that the level of the fine was too low to encourage behaviour change.
They said this was particularly the case for unauthorised absences for holidays in term time because some parents preferred to pay a £60 fine compared to the price of going away in the school holidays.
One respondent said "in this deprived area many families cannot afford the costs of a holiday out of term time. If they can, they soak up the cost of the fine as part of the holiday cost (which means the fine has zero effect)".
Interviewees also shared stories of travel agents paying fines as part of a holiday deal or of a social worker paying fines for families that they support to ensure the family's wellbeing is not adversely affected. Some also speculated that parents did not pay fines because they did not believe the local authority would proceed to prosecution.
The report notes there are inconsistencies across Wales in when fines are triggered - while 90% of RCT's fixed penalty notices in 2015-16 were issued for holidays, none were given in the Vale of Glamorgan, Caerphilly and Ceredigion for this reason.
Heather Ward from Cardiff said she had seen the inconsistencies even within the same local authority area.
"I took my daughter skiing for five days out of school and I was fined £60 for taking her out," she said.
"We went with a group of 11 people. Two other children, same age different school a mile down the road, they weren't fined and we were. So it's not consistent."
The report suggests strengthening the guidance or establishing a single national policy for Wales - where all local authorities would be told to have the same rules about when a fine should be given, rather than abolishing them.
A Welsh Government spokesman said: "We will consider the proposals in the report alongside other evidence gathered as part of our broader review of attendance policy in Wales."