this case is an exception; it does not apply in this case
Fixed polite negative expression used to state that a general rule or condition does not hold for the current situation. Often follows a statement of a rule or principle, then clarifies that the present case is excluded.
See also: この限りでない (このかぎりでない) · 限り (かぎり)
Normally we cannot accept returns, but this case is an exception.
規則では禁止されていますが、緊急時はこの限りではありません。
It is prohibited by the rules, but this does not apply in emergencies.