The change of tax class is done by the respective employer. If you want to change your tax class at Zenjob, you can do this via the Zenjob App:
Profile → Edit personal details → Tax class
A change of tax class for the current month is only possible up to the last working day of the month at 17:00 (5pm).
Please note: The employer where you have your job accounted for in tax class 1 is the main employer, which typically should be where you earn most your money. If you change to tax class 1 elsewhere, the respective employer must register as the new main employer and each subsequent employer as a secondary employer in a different tax class, otherwise the change will not take effect.
Before you change your tax class at Zenjob, ask your other employer if it is absolutely necessary. If you want to do a mini-job (up to 556 EUR) in addition to Zenjob, the employer can also tax you at a flat rate, so that you can continue to be registered at Zenjob with tax class 1.
A lump-sum taxation or flat-rate taxation (Minijob) via Zenjob is not possible.
If you have any further questions on this topic, click Submit a Request.