With Brexit day looming, UK businesses are giving up the guesswork.

In a report of Brexit's impact on the banking sector, think tank New Financial says more than 275 firms have moved or are moving some of their business, staff, assets or legal entities from the UK to the EU in preparation for Brexit, which adds up to one trillion pounds worth of assets.

And for months, every time I spoke to executives at BMW, they reiterated how heavily they have invested in the UK in general and in their Oxford Mini plant in particular, where they employ 4,500 people. But now the German carmaker admits that the "danger" of leaving the EU without a deal could lead to the closure of that plant. 

The number crunchers there say a possible 10-percent increase in their costs would be hard to absorb. And after all, their Dutch plant is gearing up to manufacture the e-Mini which is firmly inside of the European Union, where they know where they stand.

Small businesses too are feeling the impact. They tell me they are feeling the pinch. One online health & wellness start-up was raking in 2,000 pounds per week until quite recently when sales dramatically stalled. The owner categorically blames Brexit angst. He says it is the unpredictability that holds back would-be shoppers.

"They are not hitting the high street or spending online because they don't know where they will stand financially and when or if Brexit happens. The continued lack of clarity is decimating small businesses like mine," he said.

Deal or no deal, Brexit uncertainty is bad for business.