Some families come to the 11+ decision late, in Year 6 itself. The runway is short but not impossible. The right response is ruthless prioritisation.
The short answer
For an autumn-term test (Kent, Bucks, Trafford), starting in September of Year 6 leaves three or four weeks. This is realistic only if the child is already academically strong.
The longer answer
For a January or November test (Essex CSSE, NI AQE), starting in September leaves eight to twelve weeks. This is workable with focus.
The technique for a late start: skip topic work entirely and focus on full timed papers. Sit one paper, identify the two weakest topics, drill those for a week, sit another paper. Repeat.
What experienced parents do
Cut social and extra-curricular load deliberately for the prep weeks. Two hours a day is the minimum for a late-start prep; three hours is closer to what is needed.
What to avoid
Set realistic expectations. A late-start child with strong underlying ability can hit the qualifying threshold; a late-start child without that baseline rarely will. Be honest with yourself about the starting position.
Practical next step
Avoid: late-start hysteria. The child will detect parental panic and shut down. Calm focus on a tight plan beats a frantic everything-at-once approach every time. A small, deliberate action this week is worth more than a grand plan for the year ahead.