The former Republican president, who is seeking to evict his Democrat rival Joe Biden from the White House in November's vote, sent the abrupt message stating "I'm suspending my campaign" to supporters by email and text, accompanied by a link.
But clicking on it took users to a site inviting them to donate money to his campaign.
"Did you really think I'd suspend my campaign? Happy April Fools Day!" he wrote in capital letters.
The Biden team quickly clapped back with a jibe at Trump's allegedly lazy schedule.
"Trump hasn't campaigned in 16 days. So not sure what the difference is," said Biden campaign staffer Ammar Moussa.
For years, US political candidates have courted small donors, inundating supporters with text messages, emails and phone calls -- sometimes more than a dozen a day -- appealing for them to contribute financially to the cause.
They can rake in millions of dollars by doing so, a key source of cash in a country where a presidential run can cost billions of dollars.
But the tsunami of requests forces candidates to be increasingly creative to stand out from the crowd.
Trump regularly airs his legal woes, accusing the Biden administration of seeking to jail him, though he offers no evidence for his claims.
For now, the Biden campaign is ahead in the fundraising race -- an advantage it is savoring by referring to Trump, a fan of cruel nicknames, as "Broke Don."
