To maintain the illusion that the sender pays for tariffs?
Keep receipts and customs declarations on everything imported. There's a lawsuit underway and it may well be decided that Trump doesn't have the authority to levy tariffs at all under the Emergency Economic Powers Act. In that case, importers will be due a refund.[1] The Constitution says that Congress sets tariffs and the Emergency Economic Powers Act doesn't mention tariffs. As usual, Trump's strategy is to stall, probably until 2026 when this is expected to reach the Supreme Court. Congress could enact Trump's tariff schedule to resolve this, but that would lock it into law.
[1] https://www.reuters.com/legal/government/what-happens-next-u...