The hotel front desk made a mistake.

First of all, it depends on how your labor contract stipulates rewards and punishments, and whether the compensation standard for losses caused by employees' faults is specific. Under normal circumstances, employees' fault can bear part of the liability for compensation, but as far as you are concerned, you have a major fault. As a cashier, you made a serious work mistake, which directly brought economic losses to the company. If the loss is not caused by a third party or other factors, it is feasible for the company to ask you to take full responsibility. As for your 20% commitment, this is a misunderstanding in your understanding. This so-called 20% means that according to the Interim Provisions on Wage Payment, if the employer suffers losses due to the laborer's own reasons, the employer may claim compensation for economic losses according to the labor contract. Compensation for economic losses can be deducted from the employee's own salary. However, the monthly deduction cannot exceed 20% of the employee's salary. If the compensation clause of this case is stipulated in the labor contract signed between the employee and the company, the company has the right to deduct a part from the employee's salary to compensate the company's losses, but it cannot exceed 20% of the employee's salary.