A company can carryback losses up to 3 years. This means that the company can use its 525,000 2015 loss to obtain a credit for income taxes paid in the previous 3 years, 2012-2014. The calculation is as follows:
2012 Carryback: 150,000 x .35 = 52,500
2013 Carryback: 150,000 x .35= 52,500
2014 Carryback: 150,000 x .35 = 52,500
The check that Book Binder receives will be 52,500 x 3 = 157,500.
Its tax liability in 2015 will be zero, and its loss eligible for carryforward will be 525,000-450,000=75,000, since it has already carried back $450,000 of its loss (2012-2014 income).
Its liabilities in future years will be:
2016: (150,000-75,000) x .35 = 26,250. We have now exhausted all tax credits possible from the 2015 loss.
2017-20: 150,000 x .35 = 52,500