Answer:
They do not occur if you have a budget.
Explanation:
An unexpected expenses are unforseen expenses that may arise due to unforseen circumstances in business. They could impact budget in a negative way and interfere with our ability to pay bills.
To avoid the negative impact they could cause to a business, unforeseen expenses should be planned for so as to keep within the budget when the expenses arise.
Whether we have a budget or not, they should always be accounted for in our expenses to avoid damage it might cause in future.
Based on the conclusion above, the fact that unforseen expenses should not occur if you have a budget is entirely NOT true.