Secondary schools in England will have received all their applications for places by next week.

Here are five key trends in secondary school admissions that schools, local authorities and parents are currently grappling with:

1. Multi-academy trusts are naming primaries in their chains as feeder schools

The annual report of the Office of Schools Adjudicator (OSA) uncovered “an increasing trend” whereby secondary schools in multi-academy trusts (MATs) have been naming primary schools in the same chain as feeder schools in their oversubscription criteria, irrespective of local links.

Local authorities have warned that this trend could potentially lead to “a fall in successful preference allocations, possible increases in transport costs and a deficit of places in some areas”.

But some MATs have argued that having these schools as feeders helps to “support continuity in provision for children and to reflect links between schools which were members of the same MAT”.

2. Siblings of children at other schools in a MAT are also being prioritised

A number of objections are being made to schools that prioritise siblings of children in another school within the same MAT.

This is despite the OSA concluding earlier this year that there can be “unfairness” to other local children if priority for a school is given on the basis of having a sibling at any one of a number of other schools.

“It is hard to see any educational or other benefit from priority for a child to attend a particular primary school on the basis of having an elder sibling at a secondary school which is some distance away, even if both are members of the same MAT,” the OSA’s annual report said.

3. Local authorities say new free schools make it harder for them to allocate places in time

Free schools can be outside of the local authority coordination admissions process in their first year of operation, when they can handle applications directly.

But this can be challenging for local authorities when trying to allocate secondary school places. The OSA says this can leave schools and parents “in limbo at a time when decisions affecting efficient provision should have been taken and acted upon”.

Local authorities say free schools should be required to be part of the co-ordinated admissions process in their first year of opening, to help reduce the duplication of offers and the chances of children not receiving any offer.

4. And allocating places is likely to get harder with a rise in secondary school pupil numbers

The numbers in secondary schools began to rise last year and will continue to do so.

The latest forecasts, published by the Department for Education, suggest that there will be 534,000 more pupils in secondary school by 2026, compared to this year.  This amounts to a rise of 19.1 per cent over the 2017-2026 projection period.

The increase in numbers has been fuelled by a baby boom that began in 2002. The large numbers that have been passing through the primary sector are now entering secondary schools.

5. More parents are appealing secondary school places

There has been a rise in the number of secondary school appeals made by parents and heard by a panel, compared to last year.

This year, 4.8 per cent of new secondary school admissions received appeals, compared to 4.5 per cent last year. And 3.7 per cent of secondary admissions had appeals heard by a panel this year, compared to 3.6 per cent last year.

However, the proportion of upheld secondary school appeals dropped to 24.6 per cent, from 26.3 per cent last year.

As the pupil bulge, which has been affecting primary schools in recent years, moves into the secondary sector, it is likely that the number of appeals could continue to rise.