Well, that explains it

Reports have been written lately wondering why, unlike all other presidents, Trump's taxes were not subjected to a mandatory audit while he was in office.  I think we've found the answer.

From CREW, September 1, 2020:

Charles Rettig, the Trump-appointed IRS Commissioner who has refused to release President Trump’s tax returns, has made hundreds of thousands of dollars renting out Trump properties while in office, according to documents obtained by CREW. Last year Rettig said it was his decision whether to turn over Trump’s tax returns to Congress, under the supervision of Treasury Secretary Steve Mnuchin.

An analysis of Rettig’s personal financial disclosures for the last two years shows Rettig making $100,000 – $200,000 a year from two units at Trump International Waikiki. Trump made a detour to visit the property during a trip to Asia in his first year in office—a priceless promotional appearance for the business he still profits from as president. Rettig bought a 50% stake in the units in 2006, three years before the property opened. [Trump's company got 10% of total pre-sales.]

[...]

[T]here’s no mention of Trump at all in the disclosures. The two properties are referred to only as “Residential Real Estate – Honolulu, Hawaii” and “Residential Real Estate (2) – Honolulu, Hawaii.” This isn’t new. When he was first nominated, he failed to disclose the properties were in a Trump-branded building. At his confirmation hearing, he did not directly answer concerns about the properties, only saying he would serve in an “impartial, unbiased” manner.

  CREW

Confirmation hearings are really a waste of everybody's time. People lie, misrepresent and deceive all the time. Even Supreme Court nominees. I'm looking at you, Barrett, and you, Kavanaugh.

There are all kinds of reasons [Trump] doesn’t want [his tax returns] made public—including the fact that they could point to potential criminal conduct. With Trump’s name removed from some buildings as it began to hurt property values, we can only imagine how toxic it would become if a bombshell in his tax returns were released. Which means the IRS Commissioner has a vested interest in the success of the Trump brand—and of preventing anything that could damage it.

Those tax records are finally being released this week on Friday. Somehow I don't think the usual Friday document dump ploy is going to shield him.

And I'm willing to bet there isn't one single thing Trump did while president (indeed, while living) that was on the up and up.

...but hey, do what you want...you will anyway.