How to keep a farm diesel logbook

A diesel logbook is the written trail of every litre on your farm, from the day the delivery arrives to the day it is burnt in a tractor, bakkie or pump. Kept properly, it shows you where your diesel goes, makes theft and leaks easier to spot, and gives you the records you need if you claim the SARS diesel refund. Kept badly, it is a pile of slips on the dashboard.

This guide explains what a good logbook contains, how to keep it with little effort, and what to do with the records afterwards.

Why a logbook matters

There are two practical reasons.

You can see your own farm. Once every refuel is written down, you can compare vehicles, compare months and notice when a machine suddenly uses more than it should. Without records, a leak or a theft looks the same as a busy season.

SARS expects records. Farmers who claim the diesel refund must be able to substantiate the claim. SARS's rules for primary production require supporting documents, including a storage logbook and a usage logbook, and SARS can ask for them. The rules and templates change from time to time, so always check the current version on the SARS website before you rely on any summary, including this one.

The two logbooks: storage and usage

Think of the diesel on your farm in two stages.

1. The storage logbook follows the fuel into and out of each tank. Under the SARS rules, a user completes a monthly storage logbook for each storage facility, reflecting the diesel received, stored, dispensed, disposed of or lost during the month.

2. The usage logbook follows the fuel out of the tank and into the machine. The SARS rules describe a monthly usage logbook showing the diesel dispensed for use, how it was applied, which assets it powered and the purpose of each activity.

If you have a bulk tank on the farm, you need both. If you only fill from the garage into the bakkie, the usage side matters most.

What to write down

For a delivery into a tank:

• the date
• the supplier and the invoice number
• the litres delivered
• the tank that received it
• the tank level or dip reading before and after, if you take one

For every time diesel leaves a tank into a vehicle or machine:

What	Example
Date	14 October 2026
Tank	Main tank, shed 2
Vehicle or machine	Tractor 3
Litres	180
Odometer (km) or hour meter	4 512 hours
Activity	Ploughing, Block C
Who filled it	Piet

The activity column is the one people skip, and it is the one that matters most for a refund claim. SARS wants the purpose of each activity, and a general description such as "farm work" does not help you. Write what was actually done and where.

Also write down fuel that did not go into a machine: diesel that was sold, given away or lost. The SARS rules treat disposed-of fuel separately, so it should be recorded and kept out of any claim.

How often to update it

Write the entry when the diesel moves, not at the end of the month. An entry made at the pump takes a minute. An entry reconstructed from memory three weeks later is a guess, and a guess is not a record.

At the end of every month:

1. Add up the litres delivered and the litres dispensed for each tank.
2. Take a physical reading of the tank (a dipstick or tank gauge).
3. Compare the reading with what the book says should be in the tank.
4. Write down the difference and, if it is not small, find out why.

That monthly reconciliation is also the best theft and leak check you have.

Paper, spreadsheet or app

All three can work.

Paper is cheap and works anywhere, but handwriting fades, books get wet and the totals are slow to add up.

A spreadsheet adds the totals for you, but someone has to type up the slips, and entries tend to be made in batches rather than at the pump.

An app on the phone of whoever fills the vehicle puts the entry in at the right moment. AgriTrekker's mobile app, for example, works without signal and syncs when the phone is back in range, and it builds a dated logbook for each vehicle and tank. Whatever you choose, the test is simple: will the people filling the tanks really use it every time?

How long to keep the records

The SARS diesel refund page says the documentation relating to diesel purchases, together with the logbook entries and other records showing the diesel purchased and used, must be kept for five years from the date of use or disposal of the fuel, or from the refund return, whichever comes last. Keep the original invoices and delivery notes with the logbooks, and keep backups of anything digital.

A short checklist

• Every delivery is recorded against a tank, with the invoice kept.
• Every refuel is recorded against a vehicle or machine, with litres, meter reading and activity.
• Fuel that was sold, given away or lost is recorded separately.
• Each tank is dipped and reconciled once a month.
• Records and invoices are kept for five years.
• You have checked the current SARS requirements and templates for your activity.

A logbook that is simple enough to be filled in every time is worth more than a perfect one that is filled in twice a week.