Protected vs non-protected consumer: the 200-unit cliff
"Protected" domestic consumers (200 units or less, for the billing month and the prior six months) pay a materially lower base rate than "non-protected" consumers. Cross 200 units even once and the higher non-protected slab structure applies for that month — this is a genuine cliff, not a gradual slope.
One extra unit, a much bigger bill
Consuming one more unit costs Rs 5,150 more in this example — not because that one unit is expensive, but because crossing 200 units switches the rate applied to the whole consumption block. Protected status also depends on the prior six months, not just the current bill — a single high month can cost you protected status for months afterward. Run your own consumption and history through the Electricity Bill Calculator, which shows exactly how many units you have left before losing protected status.
Tariff data sourced from NEPRA — see the full versioned table on the rates reference page.