On April 13, Mr. LP applied for an automatic extension of time to file his Form 1040. He estimated that the balance of tax due was $3,800, which he paid with the extension request. He filed his return on June 20. The actual balance of tax due was $6,900, so he paid an additional $3,100 with the return.

Identify the tax issue or issues suggested by the above situations, and state each issue in the form of a question.