Could Ms. Sattig Betz’s clients prepay many months of expenses in late December if the House proposal prevails? Perhaps, but they’d need to generate more income to do that by taking more money from their retirement accounts. “I haven’t seen a simplification act that is simple in my over 40 years as a C.P.A.,” she said.

Home buyers and sellers face different decisions. What does an accountant tell a widow in California who is moving to assisted living and has her house on the market? If her dwelling is at a price point where the buyers need a mortgage that would no longer qualify for full interest deduction under the House bill, the house could be harder to sell.

So should she take it off the market during the holiday season, when sales typically dry up? It’s hard to get good guidance from the House bill. It suggests that anyone getting a mortgage after Nov. 2 would be subject to its proposed $500,000 loan cap, but who knows how that might change or if that quirk will survive a trip to a House-Senate conference?

Gina Chironis, who works out of an office in Irvine, Calif., told that widow to keep the house on the market during the holidays and consider dropping the price a little amid the tax madness. “Where there is confusion — where decision-making is made more difficult — people will tend to avoid making decisions,” she said. Hence the desire to keep the house on the market in case anyone decisive does turn up for an open house.

Many business owners, who are wondering how far their taxes might fall if they qualify for newly lowered rates or higher deductions, have asked their accountants to march line by line through their tax returns to see how they would fare next year. “Tedious, I know,” said Gary Sozzi, a New York City accountant who has done this for two clients recently.

Both clients would come out hundreds of thousands of dollars ahead under one scenario. Hooray! Were they going to hire new employees or raise current employees’ salaries? Heck, no! According to Mr. Sozzi, they feel they’ve paid way too much over the years, so they’d keep the money for themselves.

Upper-middle-class wage earners in states with high income taxes, meanwhile, face their own decisions. Should they prepay some taxes or accelerate charitable contributions? It would depend on their circumstances. Matt Talcoff, whose colleagues at his firm’s Boston office have been talking to many clients in recent days, has found that the old accounting adage about always deferring income and accelerating deductions may not be true for some people if any bill passes.