The remarks, made in a Twitter post, followed reports that Mr. Trump had expressed an interest in reining in the company. But it was not the first time Mr. Trump has criticized Amazon or its chief executive, Jeff Bezos.

Amazon’s stock price dropped in early trading Thursday after the president’s comments. But his Twitter post lacked important context about the Postal Service and relied on outdated and incorrect facts regarding Amazon’s taxes. Here is an assessment of the president’s claims.

Amazon Does Pay Taxes

Mr. Trump has made similar claims before about Amazon’s tax payments, both as president and a private citizen. After he mentioned it in August 2017, The New York Times reported:

If Mr. Trump’s point was that Amazon did not collect sales taxes — which are owed by the purchaser and collected by the retailer — it is true that the company once avoided doing so. “If this was five years ago, the tweet would be making a very compelling point,” said Carl Davis, the research director of the left-leaning Institute on Taxation and Economic Policy. Historically, “there is no doubt that Amazon used its ability to not collect sales tax to gain a competitive advantage.” But that criticism is outdated.

How outdated? In 2012, Amazon began collecting and paying state taxes in California. Since April 2017, Amazon has collected sales taxes in all states that levy one.