When you enter your pension income in the Taxfix app, you must also enter the start date of your pension. This is because it is decisive for the share of your pension income that is taxed.
The start of the pension is the date on which the pension was granted. It does not matter when the pension was first paid out.
You will find the date of the start of the pension on your pension payment statement (Rentenbezugsmitteilung). This document lists all the tax-relevant data of your pension income and allows you to easily fill out your tax return.
If you have not yet applied for the Rentenbezugsmitteilung, you can request it online from the German Pension Insurance. Here we explain how you can do this.