Tabadulat re-screens Northland Power (NPI.PR.B) every month. Each review applies AAOIFI Shariah Standard No. 21 to the latest financial data: business activity, non-permissible income, interest-bearing investments and debt, and preference shares. Our Shariah Supervisory Board oversees the process. Ratios move with the market, so a verdict can change. App users are alerted if a holding turns non-compliant.