Why are personal income tax withholdings deducted from my benefit?

The IRPF personal income tax withholding is made because cease of activity benefits are considered taxable earnings as per tax law.

The withholding rate is established as per the total sum to be received for cease of activity benefits in the current calendar year. The sum received will be based on the data you provide to the processing entity (mutual insurance company, Social Marine Institute or Spanish Public Employment Service) relating to your personal and family circumstances as concerns the right to deductions under current tax laws.