The Relief Act provides that the estimated tax payments for the 2020 tax year which would be due before October 15, 2020 will be due on October 15, 2020 without penalty. For calendar year corporations, that means the first three installments of 2020 taxes are not due until October 15, 2020. This amounts to an interest free loan of roughly 21 percent of the company’s pre-tax profits for the April, June and September installments. The applicable period is not flexible, so it applies differently to fiscal year (year ends not ending in December for tax filing purposes) corporations. The deferred estimated taxes are all due October 15, 2020. An important note is that, due to the way the deferral is written, underpayment of estimated tax penalties will not begin to accrue before October 15, 2020 and will not be retroactive.