By the time he received his visa, he flew to Australia.
Is it wrong to use "by the time" in this sentnence? Why?
What is the difference between "when" and "by the time"?
When you use "By the time he received his viza" you should go on like this"he had flown to Autralia". It means he flew to Australia without a viza.
Better to say" When he received his viza he flew to Autralia." You can also use "As soon as" instead of "when".