Best Time to Buy Prepaid Electricity for Maximum Units in 2026

If you have ever stood at the till on the 28th of the month wondering why R200 of prepaid electricity gave you barely half the units it bought you on the 2nd, you are not imagining things. The vending app is not cheating you. The system is doing exactly what it was designed to do and once you understand it, you can work it to your advantage.

This guide explains how prepaid electricity pricing really works in Gauteng in 2026, when timing your purchase makes a difference, when it doesn’t, and the practical habits that genuinely stretch a token further.

Why your Prepaid Electricity Units Shrink as the Month Goes On

If your electricity comes from City Power in Johannesburg, the City of Tshwane or the City of Ekurhuleni, you are on what is known as an Inclining Block Tariff, or IBT. It works like a step ladder.

The municipality keeps a running total of the kilowatt-hours (kWh) you buy in each calendar month. The first chunk of units is sold at the cheapest rate. Cross a threshold, and every kWh after that is charged at a higher rate. Cross another threshold, and the rate climbs again. In Ekurhuleni, the top step is severe.

The counter resets on the 1st of each month. So R200 spent on the 2nd lands you firmly inside Block 1; the same R200 spent on the 25th, after a month of geysers, kettles, lights and television, often lands inside a more expensive block. Same money, fewer units.

That is the whole “units shrink later in the month” puzzle. Nothing dishonest happens at midnight, no app gives better rates on a specific day, and switching vendors does not change the per-kWh price. The system simply remembers what you have already bought.

What the Blocks Look Like in Gauteng

Below are the official 2025/26 rates, in effect until 30 June 2026 when new municipal tariffs come into force. All figures exclude VAT; the price you pay at the till is 15% higher.

City Power (Johannesburg) – High residential prepaid

Plus a R200 monthly service and network capacity charge. Registered indigent households on the Expanded Social Package (ESP) are exempt from this charge and receive 50 kWh of free electricity each month.

City of Tshwane – Residential

City of Ekurhuleni – Tariff A2 (non-indigent residential)

Plus a R142.50 basic monthly charge for single-phase supply, introduced for the 2025/26 financial year. The third block is deliberately punitive – council policy is to push high-usage households across onto Tariff B, a flat rate that becomes cheaper once consumption exceeds roughly 820 kWh a month.

Eskom Direct Customers: The Rules Changed in April 2025

If you buy your electricity directly from Eskom, common in parts of Midvaal, Lesedi, and on the edges of Tshwane and Ekurhuleni, your situation is now completely different from your municipal neighbours.

From 1 April 2025, Eskom removed the Inclining Block Tariff for its Homelight 20A, Homelight 60A and Homepower 4 residential tariffs. Customers now pay a flat rate per kWh, regardless of how much they buy in a month. A further 8.76% increase took effect on 1 April 2026, putting Homelight 20A at roughly R2.71 per kWh and Homelight 60A at around R3.44 per kWh.

For Eskom direct customers, timing genuinely does not matter – the first kWh of the month and the last cost exactly the same. The trade-off is that Eskom raised fixed monthly charges sharply on Homepower customers in 2025, with the service component on Homepower 4 jumping by about 88%. The overall impact depends on how much you use.

In short: block-tariff timing tricks apply to municipal prepaid customers. They do not apply to Eskom direct customers.

Does Buying Early in the Month Really Help?

For City Power, Tshwane and Ekurhuleni customers, yes but with an important nuance.

The advantage is not from “buying” earlier in itself. It comes from staying in Block 1 for as long as possible. What the system tracks is your cumulative kWh purchased that calendar month, not how many separate transactions you made.

That means splitting a R1 000 purchase into five R200 purchases on different days will not give you more units. The moment your monthly total crosses a threshold, every kWh above it is charged at the higher rate, regardless of when or how you bought it.

What does help:

• Making your largest top-up of the month early, so most of it clears at the Block 1 rate.
• Reducing total consumption, which keeps you inside Block 1 for longer.
• Watching usage in the last week – that is when an extra geyser-heavy day quietly tips you into a more expensive block.

A worked example

Take a Johannesburg household on City Power High, using around 500 kWh a month.

• R500 spent on the 2nd, before any usage has been logged: the entire purchase (around 163 kWh including VAT) falls inside Block 1 at roughly R3.06 per kWh.
• R500 spent on the 26th, after 400 kWh has already been bought that month: the first 100 kWh of the new purchase sits in Block 2, and the rest spills into Block 3 at about R4.00 per kWh including VAT. The same R500 might only buy 130–135 kWh.

The household paid the same amount and ended up with around 30 fewer units, purely because of where they sat on the block ladder.

The effect is most dramatic in Ekurhuleni. Crossing 700 kWh in a month sends the rate to R11.44 per kWh excluding VAT, more than four times the Block 1 rate. A R500 top-up in that band buys around 38 kWh.

Winter, “Seasonal” Pricing, and What the Rumours Get Wrong

A common belief is that municipal prepaid prices “go up in winter”. The reality is more specific:

• Standard residential prepaid tariffs do not have seasonal pricing. Your block rates in Joburg, Tshwane and Ekurhuleni are the same in July as in November.
• The annual price increase is what most people are actually feeling. Eskom’s increases take effect on 1 April; municipal increases take effect on 1 July. Because 1 July sits right at the start of Gauteng’s coldest months, the new tariff lands at the same time you start running the geyser and heater harder. It feels like a winter spike. It is actually the annual hike colliding with seasonal consumption.
• Genuine seasonal pricing does exist, but only on Eskom’s Time-of-Use Homeflex tariff (used mainly by solar households) and on commercial tariffs, where the High Demand Season (June–August) is more expensive than the Low Demand Season.

For ordinary prepaid users, winter does not change the price per unit. It simply pushes you deeper into the expensive blocks much faster, because you use more.

Related: How to Reduce Electricity Costs During Winter in Gauteng: A 2026 Guide

Common Myths Worth Ignoring

• “Buy at midnight to get more units.”
  No. The block system is a monthly counter, not a daily one.
• “Tuesdays are cheaper.”
  No day of the week affects the price.
• “Splitting purchases gives you more units.”
  No. The system tracks cumulative monthly kWh, not the size of each transaction.
• “All prepaid users pay the same.”
  No. Your rate depends on your municipality, your tariff code, and whether you are an Eskom direct customer or not.

Practical Tips to Stretch Your Token

• Know who actually supplies you.
  The supplier name is usually printed on your meter or vending slip. The rules differ.
• Buy your big top-up early in the month if you are on a municipal block tariff.
• Track your monthly kWh.
  Most prepaid meters display the running balance – note it on the 1st and again on the 15th.
• Manage the big consumers first.
  Geysers, heaters and tumble dryers are usually what tip households into higher blocks. A geyser timer often pays for itself within months.
• Re-check your tariff code each July.
  In Ekurhuleni in particular, the right choice between Tariff A and Tariff B depends on whether your monthly usage is above or below about 820 kWh.
• Register for Free Basic Electricity if you qualify.
  City Power gives qualifying indigent households 50 kWh free per month and exempts them from the R200 service surcharge. Tshwane and Ekurhuleni run equivalent programmes.
• Use cheap vending channels.
  Some apps and retailers add a transaction fee; FNB, TymeBank and African Bank typically charge little or nothing.

The bottom line

If your supplier is a municipality, your per-unit price climbs the more you buy in a month, and timing your big top-up to early in the month genuinely helps. If your supplier is Eskom directly, the per-unit price no longer changes with volume and timing makes no difference at all.

Either way, the single biggest factor in how much value you get from each prepaid purchase is not when you buy – it is how much you use. Block tariffs reward restraint. Flat rates reward efficiency. Both reward households who understand their bill.

Important Information

This article is for general information only and is not financial, legal or tariff-specific advice.

• All rand-per-kWh figures shown are excluding VAT. The price you actually pay at the vending app or till is 15% higher.
• Source and effective dates. Municipal figures are drawn from the approved 2025/26 schedules of the City of Johannesburg (City Power), the City of Tshwane and the City of Ekurhuleni, effective 1 July 2025 to 30 June 2026. Eskom figures are from the NERSA-approved 2026/27 schedule, effective from 1 April 2026.
• Tariffs change annually. Municipal tariffs are next due to be revised on 1 July 2026; Eskom direct tariffs on 1 April 2027. Always check the current schedule on your municipality’s website before making financial decisions. NERSA-approved figures are themselves occasionally revised after publication – the 8.76% Eskom increase for 2026/27, for example, was an upward correction from an earlier 5.36% figure.
• Your tariff code matters. Within each municipality there are several residential categories (Lifeline, Indigent / ESP, A1, A2, High, Tariff A, Tariff B and others). The rates shown here are for the most common non-indigent residential prepaid category in each metro. Check your meter, account or vending slip to confirm which category applies to your household, or contact your municipality’s customer care.
• Worked examples are illustrative. Your actual results will depend on your household’s usage, supplier, tariff code, and any arrears or service charges on your account.
• Free Basic Electricity programmes and indigent-registration requirements differ between municipalities and change over time. Eligibility and kWh allocations should be confirmed directly with your municipality.
• No endorsement is intended of any vending channel, bank or retailer mentioned. Transaction fees and availability change.