The short answerTo buy diesel in bulk, work out your monthly volume, choose 50 ppm or 500 ppm, install compliant storage with your municipality’s approval, and buy from a licensed wholesaler. Compare delivered prices against the monthly wholesale list price, agree payment terms, and check seals, meter readings and the certificate of analysis on every delivery.
1. Work out your volume
Start from what you burn. For a fleet: vehicles × kilometres a month × litres per 100 km. For plant and generators: machines × hours a month × litres an hour. Add a buffer for peaks such as harvest or a shutdown. Our diesel volume estimator does the sums.
2. Choose the grade
50 ppm for modern vehicles and any engine with exhaust after-treatment; 500 ppm for older engines, plant, tractors and generators where the manufacturer allows it. Both are made to SANS 342. If you need both, you need two tanks.
3. Get storage right
Bulk diesel needs a compliant tank. Above-ground tanks follow SANS 10131 and the handling side follows SANS 10089. Most municipalities require a flammable-liquid certificate from the fire department, and tanks need bunding (commonly 110% of the largest tank's capacity), earthing, signage and fire extinguishers. A self-bunded tank meets the bunding rule by design. See diesel tanks and bowsers.
4. Check the supplier
- A wholesale licence from the Department of Mineral and Petroleum Resources. Ask for the number.
- A registered company with a physical address and a landline.
- A certificate of analysis for every batch, and sealed, metered deliveries.
- Payment only into a company bank account. Never into a personal account.
In 2026, with adulterated diesel in the market, these checks matter more than ever. Read how to spot adulterated diesel.
5. Understand the price
The DMPR publishes a wholesale list price for diesel every month, adjusted on the first Wednesday. It includes the basic fuel price (the cost of importing the product), levies, transport and margins. Bulk prices are negotiated from there: volume, distance and payment terms move them. Compare delivered prices, and check how long each quote is valid; diesel can move more than R3 a litre in a month. Follow the monthly changes on our diesel price page.
6. Agree payment terms
New customers usually pay upfront. Regular buyers can apply for a fuel account with credit terms. Ask how price changes are handled on orders placed before an adjustment and delivered after it. Apply for a Fuel-It account.
7. Take delivery properly
- Dip your tank before the truck arrives.
- Check the seals and match the numbers to the delivery note.
- Watch the meter, and compare the metered quantity with your after-delivery dip.
- Take and keep a sealed, labelled sample.
- Sign only once the documents match what you received.
8. Keep the records
File the tax invoice, delivery note and certificate of analysis for every load. If you farm, mine or work in forestry, these are the foundation of your SARS diesel refund claim; SARS requires records to be kept for five years. See our diesel refund guide.
Sources
- SARS, Diesel Refund System (updated 22 September 2026)
- SAnews, “All fuel prices to increase from Wednesday”, 31 August 2026
- Petroleum Products Act 120 of 1977