We were “accidental deferrers” with our late summer born DC.
We knew we would be unavoidably having to relocate half way through reception year. So we didn’t apply to start reception in our old town, and couldn’t apply for new as we weren’t living there yet - same for following year.
The plan was to reassess once we were living in the new place, to decide whether to take an in-year admission place with correct age if it came up, or (after Sept), one for the year below. Head said we could be considered for either.
In the end, a place came up after Easter with the correct age cohort, and we took it.
DC missed two terms of reception, but joined the correct age class.
I know everyone always says this is the worst of both worlds, but actually I think it was hugely beneficial for DC.
They got to have those crucial 8 extra months growing up a little bit more, which I think made all the difference for maturity and school readiness.
They actually caught up really quickly academically, made lots of friends, were fine going into Y1 a term later, were very ready for high school in Y6, very high scores in Y6 SATS, and now still flying academically in their correct age group - tbh they were quite bored towards the end of primary, so being in the year below would probably have been very frustrating.
For my child, the deferred start happened to be perfect, but they didn’t need it to be ongoing, as there are no issues with academics.
I would say if you think there will be an issue with learning, I would hold back a year. If you think it is more maturity and school readiness, where a few months at this age can make a big difference, I would seriously think about if you can start later in the year, but stay with the correct age.