It was the promise that launched a campaign, chanted back at rallies until it became a call and response. "Mexico will pay for the wall," the candidate said, and said again, often adding "100 percent." [4] Years and roughly fifteen billion dollars of construction later, the question of who paid has a documented answer, and it is not Mexico. It is you.

Mexico never sent a check

Start with the simple fact. Mexico never paid for the wall, never agreed to, and its president said flatly that it would not. [2] No bill was sent, no fund was set up, and no Mexican money built any segment of barrier. The promise was not partially kept or paid in some indirect way the slogan could survive. On its own terms, the who-cuts-the-check terms it was made on, it was simply broken.

Who actually paid

Now follow the money that did build it. The barrier that went up, mostly replacement fencing rather than new wall, was paid for by the United States, in two ways. Congress appropriated some of it directly from federal funds, which is to say from taxpayers. [3] For the rest, after Congress declined to provide what he wanted, the President declared a national emergency and redirected roughly ten billion dollars that had been appropriated for the military, including money meant for bases and counter-narcotics. [3] The Government Accountability Office, the federal government's own watchdog, later found that some of that redirection broke the law. [1]

Who paid for the border wall ($ billions)
US taxpayers + redirected military funds15Mexico0
Border barrier construction was funded by US appropriations and redirected US military funds; Mexico paid nothing. Source: Congressional Research Service. [3]
Data
US taxpayers + redirected military funds15
Mexico0

The honest accounting is not complicated. A promise was made that a foreign country would pay, the foreign country did not pay, and the cost landed on American taxpayers and, unlawfully in part, on the American military's own budget. [1][3] You can support a border wall and still want the truth about who financed it. The slogan said Mexico. The receipts say the Pentagon and you.