VAT is a monthly tax and the system enforces the rhythm with a combination of interest and penalties that stack quickly. When a return is not filed or the tax not deposited by the due date, interest runs from that day on the outstanding amount, and a separate penalty attaches to the non-filing itself even if the eventual tax is zero. The stacking is the dangerous part. A business that slips three months accumulates three penalties on top of three months of compounded interest, and if a staff member filed late but the department had already asked, the figures grow further. Because every month carries its own return and its own penalty, a single missed quarter can generate a bill that surprises even careful accountants. The fastest repair is to file the missing months as soon as discovered and pay the accumulated interest, because the clock stops the day the liability is settled. Most filings carry no genuine dispute, only delay, and delay is the expensive component. Regular calendar reminders, a dedicated person for the return and a zero-tolerance rule for the deadline are cheaper than any penalty the department publishes.