SA Municipal Utility Tariff Engine 2025/2026 IBT

Incline Block Tariffs • Electricity (kWh) & Water (kL) Forecaster

Total Monthly Bill
R 0.00
Total with 15% VAT ~R0.00/day
Electricity Total 600 kWh
R 0.00
Effective Rate R0.00/kWh
Water (Potable) 15 kL
R 0.00
Effective Rate R0.00/kL
Sanitation & Sewer 10.5 kL
R 0.00
Discharge Factor 70% vol
Fixed Fees & VAT 15% VAT
R 0.00
Basic Service Fee R0.00

Tariff Threshold Proximity Caution

You are currently utilizing Block 1. Keep consumption under 600 kWh to avoid stepping into the punitive Block 2 rate (+28% more expensive).

Marginal Cost of Next Unit
R3.45 / kWh

Electricity Consumption

Incline Block Tariff (IBT) stepped kWh billing

Block 1
kWh
0 kWh 350 kWh (Lifeline) 600 kWh (Domestic Cap) 1000 kWh 2000+ kWh
Typical:
IBT Stepped Rate Ladder 550 / 600 kWh in Block 1
Tariff Block Units (kWh) Rate / kWh Cost (R)

Water & Sanitation Usage

Incline Block Potable (kL) + Sewerage discharge

Step 2
kL
0 kL 6 kL (Free Base) 15 kL (Family Avg) 35 kL (Punitive Step) 60+ kL
Typical:
Water Incline Steps 16.5 kL in Step 3
Service Component Units (kL) Rate / kL Cost (R)

How Incline Block Tariffs (IBT) Work

Incline Block Tariffs are tiered pricing mechanisms approved by NERSA and municipal councils. As your monthly consumption crosses predetermined volume thresholds, subsequent units are billed at progressively higher, punitive rates. This cross-subsidizes free baseline services for indigent households and incentivizes resource conservation.

Prepaid vs Postpaid Fixed Charges

While prepaid meters traditionally avoided fixed monthly service fees, municipalities (including City Power Johannesburg and City of Cape Town) have introduced fixed network availability fees to recover grid infrastructure costs regardless of token sales. Always factor in basic service charges when comparing STS prepaid to credit meters.

Why Marginal Savings Matter

When investing in solar PV, solar geysers, or greywater systems, calculate payback against your top marginal tier rather than your average tariff. If you use 800 kWh/month in Cape Town, the first 200 kWh you generate with solar offsets the highest Block 2 rate (R4.43/kWh), delivering rapid capital payback.