I had some exceptional income in 2022 which resulted in me having an IT liability of about 10k more than normal, resulting in a significant enough balance of tax to pay, which I allowed for. I'd like to not pay 100% of this as my preliminary tax for this year as I expect my income to return to pre-2022 levels. I'm am looking at the DD option of paying 105% of the pre-preceding year's liability, but I think I'd prefer to remain with the lump sum option for cash flow purposes. If I go with the option to pay 90% of the final tax liability for the current year of assessment do I have to notify Revenue or do I just make the payment in November? What if it ends up being <90% of the actual liability? Are Revenue likely to penalise me if I pay the balance in January 2024? (I am reasonably confident I can get it fairly accurate).