President Trump attends a roundtable discussion on tax policy on April 5 in White Sulphur Springs, W.Va. (Evan Vucci/AP)

It is tax day, the day when Americans giddily address one of the two certainties that await them. What more robust joy could there be for an American citizen than rendering a hefty check unto the Internal Revenue Service’s seizers? There could be no larger joy. Americans love taxes, and vice versa.

One ebullient taxpayer in the United States is a man named Donald Trump. He enjoys paying his taxes so much that he, at one point, posted a photograph of himself doing so on Instagram.

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Signing my tax return....

A post shared by President Donald J. Trump (@realdonaldtrump) on

Those stacks of documents next to Trump in those photos reflect the complexity of his business holdings. Although his net worth has declined in recent years (largely a function of the softening retail rental market in Manhattan), he’s still worth an estimated $3.1 billion, according to Forbes. That net worth is calculated from a variety of marketing deals, real estate holdings and rental fees. It’s a complicated business, the Trump Organization, and that pile of papers Trump signed in 2015 is a testament to that fact.

Of course, things are slightly different now than they were then. Trump is now president of the United States, and some consider his properties an avenue to demonstrate loyalty to or curry favor with him. Trump properties have been paid $1.5 million since the beginning of 2017 by political action committees, including from Trump’s 2020 reelection campaign. The Trump Organization has made an undetermined amount of additional profit from government agencies, business groups and foreign groups. To avoid constitutional questions about the president making money from foreign actors, the Trump Organization has donated more than $150,000 it earned from foreign governments to the Treasury. For Trump, unlike past presidents, did not fully divest from his stake in his private business upon entering the White House.

A lot of money is sloshing around in Trump’s tax returns and, as of Jan. 20, 2017, where it’s sloshing and how big the waves are (to exhaust the metaphor) is more important than ever.

But, as you know very well by now, Trump will never release those tax documents to the public. He has claimed repeatedly since announcing his candidacy that he is unable to release his tax returns because they are under audit. That is not an indisputable excuse: There is no legal obstacle to Trump releasing his returns. What’s more, he revealed during the campaign that his returns before 2008 were not under audit — but he refused to release them anyway.

The result is that we know less about Trump’s finances than about the finances of any president in at least 50 years, according to our analysis of historical tax information. Every other president since Jimmy Carter has released tax returns for each year of his presidency except the last (because those returns are filed after the president leaves office).

For Trump, we have one partial return from 2005 that was leaked to journalist David Cay Johnston and then published. Other than that, nothing.

That we don’t know what Trump’s tax returns have said became a significant issue in late 2017 as the president argued without evidence that his party’s proposed tax cuts would hurt his bottom line. (Outside analysis contradicted that claim.) That he won’t reveal how much he earned overall last year — the first year during which his policies might affect his income — is probably more important.

The president for whom tax returns would offer the most transparency and potential accountability simply refuses to release them. Oh, well! Unless Congress implements a mandate to release tax information (a bill that would face a presidential veto, we’d assume), Trump is not going to release his tax returns at any point during his presidency. He was never going to release his tax returns, regardless of whether they were under audit; he’s certainly not going to release them now.

A third certainty to add to the mix.

Update: Obama administration official Seth Hanlon noted on Twitter that Congress could release Trump’s tax returns — if the requisite Republican-controlled House or Senate committees chose to do so.