Most VAT filing problems we see are not disputes about the amount owed, they are missed deadlines caused by no single person owning the filing calendar.
A practical fix is a shared calendar with each filing date, the person responsible for preparing it, and a review date at least three working days before submission, giving enough room to catch errors before they become late filings.
Where a business has multiple registrations or crosses into withholding tax obligations as well, the same calendar should carry those dates too, so nothing is tracked in someone's memory alone.