We use this expression to say that something is absolutely sure or completely normal or necessary.
You can use this phrase in ………… language.
Spoken
Written
Formal
Informal
Example 1
A: If you want to have a party at work, you’ll have to ask the boss for her permisson.
B: Of course. It goes without saying.
Example 2
A: Do you think you will be at John’s wedding?
B: Of course. It goes without saying. We’ve been best friends for years.