More appeals were lodged in Cornwall last year following the refusal of a school place application, new figures show.
School leaders’ union NAHT said place planning has become uncoordinated in an "increasingly fragmented" school system, as it called for a plan to guarantee a school place for every child.
Most appeals are made when an applicant has not received an offer of a place at their first preference school. However, appeals relating to other transfers at the start of the school year are also included.
Figures from the Department for Education show 221 appeals were lodged in Cornwall by the start of the 2023-24 school year – up from 208 the year before.
Across the country, 56,684 school admissions appeals for 2023-24 places were lodged, up 7% on the year before.
Paul Whiteman, NAHT general secretary, said: "Starting a new school is a huge moment in a child’s life, so it is understandable that getting their first choice is a priority for parents and it is right that they have access to a clear and fair appeal process to try to secure this.
"The problem is that the increasingly fragmented school system lacks a co-ordinated approach to place planning."
He added local authorities retain responsibility for ensuring sufficient school places, but "no longer have the powers and resources needed to do so".
"This means planning can appear haphazard, decisions are often made in isolation without considering the implications for local families, and as a result new schools and places are not always commissioned where they are most needed," he said.
He added a national strategy to guarantee there are enough school places for every child is needed.
Of the appeals lodged in Cornwall, 159 were heard by an appeals panel – 48 of them (30%) were successful.
This was higher than the rate across England where 8,490 of the 42,345 appeals (20%) heard were successful.
Pepe Di’Iasio, Association of Secondary and College Leaders general secretary, said: "The number of appeals lodged by parents reflects pressure on places in oversubscribed schools which fluctuates because of things like new housing in popular catchment areas."
He added demand is often driven by Ofsted ratings, leaving other schools undersubscribed with available places.
"This is one of the reasons why we are pleased that single-word Ofsted judgements are being scrapped and that the new government is committed to providing more support to schools where this is needed," he said.
A Department of Education spokesperson said: "It is the responsibility of the local authority to ensure there are sufficient school places for pupils who need them.
"Each school has an admission authority to set its admission arrangements including the oversubscription criteria it will use to allocate school places if more applications are received than there are places available."