In the U.S., there are misconceptions regarding the $600 1099-MISC threshold. Form 1099-MISC is a form that businesses ("payers") are generally required to issue for payments at/over $600 to contractors. The truth is, the $600 limit is only relevant as the threshold for the payers' obligation to report to the IRS the payments made to the contractor; however this has nothing to do with the contractors' obligation to pay taxes on income under $600.
For example, if a contractor earns $500, they might not receive a Form 1099-MISC from the business that paid them, because the business was not required to file Form 1099-MISC. In this case, the income is still taxable to the contractor even though it is less than $600.