Business owners can take the employee retention credit or the Social Security tax deferral, which lets them delay payments until 2021 and 2022, but the downside is that the money will be taken out of the loan from the Paycheck Protection Program, said Megan Niedermeyer, head of legal and compliance at Gusto, a payroll company.

More esoteric provisions have been loosened in the relief legislation. One removes the cap on excess business losses. It used to be limited to $500,000 a year, similar to the $3,000 limit on personal investment losses from previous years. Now, any amount of business loss can be applied this year, and the loss could effectively take a company’s tax bill down to zero, Mr. Finkle said.

Another change is on how a net operating loss is counted. Business owners can now look back five years for their 2018, 2019 and 2020 filings and count those losses. Because the tax rate was higher before the 2017 tax changes, losses from then are worth more today. “You could end up with a refund,” Mr. Finkle said.

Personal planning opportunities around these tax incentives could benefit families for generations.

If people have the stomach for it, paying tax now, in some cases, is a shrewd move. One recommendation is to convert a traditional retirement account, where money goes in tax free but is taxed when it comes out, to a Roth I.R.A., where the money is taxed first but then grows tax free.

The conversion is a good move now because the value of the retirement account is surely lower than it was because of the decline in the stock market and much lower than it will be when the market eventually recovers. But the tax has to be paid now, at a time when cash may be tight, said Ken Van Leeuwen, managing director and founder of Van Leeuwen & Company.

For corporate executives who have incentive stock options, now is the time to exercise them and pay the tax if the stock value is depressed. Mr. Van Leeuwen said he had advised executives who believed in the future of their company to pay the tax outright, instead of selling shares to cover it.

“It’s hard to get over that hump,” he said. “When you say it’s time to exercise your I.S.O.s, they’re actually buying a stock and taking on more risk. That’s a harder one right now.”