In 2015, Paul, who is single, has a comfortable salary from his job as well as income from his investment portfolio. However, he is habitually late in filing his federal income tax return. He did not file his 2015 income tax return until December 4, 2016 (due date was April 18, 2016) and no extensions of time to file the return were filed. Below are amounts from his 2015 return:

Taxable income ................................................................  $140,000
Total tax liability on taxable income ..............................       32,271
Total federal tax withheld from his salary ....................       26,808

Paul sent a check with his return to the IRS for the balance due of $5,463. He is relieved that he has completed his filing requirement for 2015 and has met his financial obligation to the government for 2015. Has Paul met all of his financial obligations to the IRS for 2015? If not, what additional amounts will Paul be liable to pay to the IRS?