At-will employment

A US employment arrangement with no direct UK equivalent. Under at-will employment, either side can end the relationship at any time for any lawful reason, without notice or severance.

Nothing comparable exists in UK law as a general default. Employees have statutory notice rights, and unfair-dismissal protection applies after the qualifying period. A probation period is not the same thing. For genuinely irregular work, the UK questions are employee, worker, or self-employed status and the rights that follow from that classification.

Related: 1099 contractor, National Minimum Wage.