What is the minimum heating oil order?

500 litres is the usual starting point

Orders on Fueltool start at 500 litres. A typical 500 litre order today costs about £606, including 5% VAT and delivery.

That is in line with the market. The Competition and Markets Authority (CMA) called 500 litres the industry standard minimum in Great Britain in its 2026 study, and found there was demand for smaller orders that most distributors don't meet. In Northern Ireland, lower minimum orders are much more common, and the Consumer Council's price checker publishes average prices for 300, 500 and 900 litres.

Why there is a minimum

It isn't a legal limit. In its October 2026 response to the CMA, the government said the regulations do not set a minimum order volume, and that the smallest quantity that can be delivered depends on the approved operating range of the measuring equipment on the tanker. Accurate measurement is the point: the government said it is vitally important that customers get an accurate delivery.

Cost plays a part too. Each delivery has to cover the tanker and driver, so small orders cost more per litre. On today's typical prices, 1,000 litres works out 1.4p a litre cheaper than 500 litres.

Is this changing?

The CMA's final report on 15 July 2026 recommended a review of the rules on minimum order volumes, so households could buy smaller amounts, and that suppliers clearly signpost their minimums, the reasons for them, and any payment plans. On 13 October 2026 the UK government agreed, and said it will examine whether the rules and industry guidance are being applied in ways that unnecessarily limit choice. Its response covers Great Britain only; in Northern Ireland the recommendation is for the Northern Ireland Executive to consider. As of October 2026, no change to the minimum order rules has been announced.

If 500 litres is hard to manage

• Ask about payment plans. The CMA found payment plans widely available across the UK but not always clearly signposted. See spreading the cost of heating oil.
• Look for help. In 2026 the UK government and each devolved government announced support for households struggling with oil costs; in England it is being delivered by councils through the Crisis and Resilience Fund. Our guide to help with heating oil costs covers each nation.
• Don't wait until you're nearly empty. UKIFDA, the fuel distributors' trade body, advises keeping at least 500 litres in the tank wherever possible, as a buffer in case of high demand, severe weather or delivery delays.

Is there a maximum?

The real limit is your tank. Which? advises filling a tank only to around 80% to 90% of its capacity, to avoid spills, so you need at least 500 litres of space below that level. For very large orders, HMRC's rules give the reduced VAT rate automatically on deliveries of up to 2,300 litres to one site on one day; above that, the reduced rate depends on the oil being for a qualifying use such as heating a home.

To see what 500 litres costs at your address today, compare prices for your postcode.