You may be entitled to a prompt payment discount from the Tax and Customs Administration in certain cases if you pay the entire income tax amount owed in one go before the first payment date. Be aware, though, that in 2022 this applies to provisional income tax assessments for 2022 (which you can also pay in instalments) and not, for instance, to the income tax assessment for 2021, which you only receive after filing your tax return for that year.