Short of a free delivery threshold, the answer comes down to one comparison: the amount you need to add against the delivery fee. If the gap is smaller than the fee, adding something you would actually use is usually cheaper than paying. If the gap is bigger, paying the fee is normally the better move, unless you really need the extra item.
Use the calculator above to run your own numbers. The rest of this guide explains the logic, with worked examples you can check yourself.
How the free delivery threshold decision works
There are only two routes to the checkout, and each has a clear total.
- Pay the fee: basket total + delivery charge.
- Reach the threshold: the threshold amount itself, with delivery free.
The amount you need to add is simply the threshold minus your basket. Compare that gap with the delivery charge. That one comparison tells you whether you are being nudged into overspending.
Worked examples
Take a delivery charge of £4.99 and free delivery on orders of £50 or more. Here is how the choice changes as your basket gets closer to the line.
| Basket | Gap to £50 | Pay delivery | Add to reach £50 | Verdict |
|---|---|---|---|---|
| £42.00 | £8.00 | £46.99 | £50.00 | Pay the fee unless you want the extra £8 of items |
| £46.00 | £4.00 | £50.99 | £50.00 | Adding is £0.99 cheaper overall |
| £48.00 | £2.00 | £52.99 | £50.00 | Adding is £2.99 cheaper overall |
At £42, you would spend £3.01 more in cash by adding items (£50.00 against £46.99). That is only worth it if the extra £8 buys something you would have purchased soon anyway. At £46 and £48, the gap is smaller than the £4.99 fee, so reaching the threshold costs less than paying for delivery and you still get the extra goods.
The break-even point
The break-even gap is the delivery fee itself. In this example, a gap of £4.99 or less makes adding to the basket the cheaper route in pure cash terms. Above £4.99, you are paying more than the fee just to avoid the fee.
Look at the fee as a share of your basket
A £4.99 fee on a £42 basket is about 11.9% on top. On a £150 basket it is about 3.3%. Delivery matters most on small orders, which is why thresholds are designed to push baskets upward.
Does a voucher code count towards the threshold?
This is where people get caught out. Retailers differ: some measure the threshold before a discount code, others after it. Check the delivery terms on the retailer's help page, because the checkout may only reveal the fee at the last step.
Example: a £54 basket with a 10% code becomes £48.60. If the threshold is measured after the discount, you drop below £50 and the £4.99 fee returns, making £53.59. Adding about £1.56 of items at full price makes £55.56, which is £50.00 after 10% off, and delivery is free. You can model the discount side with the Discount Calculator, or see how a sale price and a code combine in the Stacked Discount Calculator.
If you are weighing a free delivery offer against a money-off code, the Voucher Comparison Calculator helps you see which leaves you better off.
When it is not worth reaching the threshold
- You are buying a filler item you do not need. Spending £8 on something that sits in a cupboard is not a saving.
- The item will cost more elsewhere. Check the price per unit before bulking up, using the Price Per Unit Calculator.
- Returns are not free. Free delivery is not always free returns. If you might send something back, a return fee can cancel the saving.
- You are splitting a shipment. Some retailers charge per delivery, so items that dispatch separately may not all count towards one threshold.
Other ways to avoid or reduce delivery charges
- Click and collect: many UK retailers offer free or cheaper collection from a store or pickup point.
- Delivery passes: divide the pass price by your usual delivery fee to find how many orders it takes to pay for itself. Illustratively, a £30 yearly pass against a £4.99 fee needs 7 orders (6 orders cost £29.94, which is just under £30).
- Free delivery codes: some codes remove the fee with no minimum spend. Browse PrimeVoucher's stores to see what is available.
- Plan shared orders: combining a household's needs into one order is the most natural way to reach a threshold without waste.
- Cashback: if you were going to spend the money anyway, check what you would earn back with the Cashback Calculator.
Quick checklist before you checkout
- Work out the gap: threshold minus basket.
- Compare it with the delivery fee.
- Ask whether you would buy the extra item anyway.
- Check whether your voucher code is applied before or after the threshold.
- Check the returns policy and any collection option.
Thresholds and fees change often, so always confirm the current figures at the retailer's checkout. The numbers above are examples to show the method, not live offers.