It comes before the closing punctuation as shown below:

Letters which are traditionally punctuated are said to have a closed punctuation style.

If a part given in parentheses has a fairly close connection to the sentence, the closing punctuation mark is used after it.

This sentence is also missing its closing punctuation.

This field ends with a period (after the date), a comma (if there is no date) or other closing punctuation.

Following a brief direct quotation, the citation is placed after the closing quotation marks but before the closing punctuation:

It is used as a closing punctuation mark of emphatic sentences and clauses, and as a non-closing punctuation mark finishing inserted sentences.

When used as a sentence closing punctuation mark, the pitch is cadent, thus decreased towards the end of such a sentence, or semi-cadent, indicating a half-finished thought, or there is no change in pitch.

When a quotation is followed by other writing on a line of text, a space follows the closing quotation mark unless it is immediately followed by other punctuation within the sentence, such as a colon or closing punctuation.

Candidates at the Higher Tier should be sufficiently familiar with these documents to be able to construct them from notes or brief instructions. 3b Candidates must be able to use either open or closed punctuation with accuracy and consistency.