Free heating oil guide
The safest rule is to order well before your tank is nearly empty, so you are never forced to accept whatever delivery is available. Demand and prices tend to rise through the coldest months and around cold snaps, while summer is usually quieter. Larger orders cost less per litre, so filling up in one delivery beats several small top-ups.
Nobody can reliably predict where heating oil prices will go, so this is guidance on timing rather than a forecast. To work out your own dates, use the run-out date calculator and delivery deadline planner.
The most reliable way to time an order is to work back from when your tank will run dry. Divide the oil in the tank by your daily usage to estimate the days of oil you have left, which gives an approximate run-out date.
From that date, subtract the delivery lead time your supplier quotes, then subtract a safety buffer for slippage. The result is your latest safe order date. Ordering by then keeps you clear of an emergency premium and gives you the pick of suppliers. To fill to a safe 85% level, order the difference between 85% of your tank capacity and the oil already in it.
There are no price figures here on purpose. Heating oil tracks the wider oil market and cannot be forecast, so timing advice is about your deadline and the season, not a prediction of prices.
When to order, worked back from your run-out date:
days_left = oil_now / daily_use
runout_date = today + days_left
last_safe_date = runout_date - lead_days - safety_buffer
lead_days = 7 days (verified 2026-07-28)
safety_buffer = 3 days (verified 2026-07-28)
order_litres = tank x 0.85 - oil_now (fill to 85%)
No price figures here: nobody can predict heating oil prices.
This is guidance on timing, not a forecast. | Figure | Value | Source | Verified |
|---|---|---|---|
| lead days default | 7 days | Indicative estimate - not independently sourced | 2026-07-28 |
| safety buffer days | 3 days | Compare My Heating Oil editorial policy, order-by safety margin | 2026-07-28 |
| tank safe fill pct | 0.85 ratio | OFTEC guidance: tanks are filled to 80-90% of stated capacity to allow expansion | 2026-07-28 |
Your deadline comes first. If you are close to empty, timing the market is beside the point: running dry risks air in the fuel line, a boiler lockout and an emergency callout. Keep a comfortable margin so you can choose when to order.
Season shapes demand. From late summer into winter, demand and prices tend to firm as households fill up, and cold snaps concentrate orders. Summer is usually quieter, so an off-season fill often means more supplier choice and shorter lead times.
Lead time varies by area. Remote rural postcodes, islands and the far reaches of Scotland and Wales can carry longer lead times, especially when every tanker is busy. A longer lead time pushes your latest safe order date earlier.
Order size and buying together. Larger orders cost less per litre, so filling up in one delivery usually beats several small top-ups. Grouping an order with neighbours, or joining a local buying group, can bring the per-litre price down further.
When you are ready to order, compare local suppliers for your postcode and buy before your deadline.
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Avoiding emergency deliveries
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