Five variables, three of which nobody publishes in advance
Three charges get folded into one sentence — "there is a fee on top" — and they are not the same kind of thing. One is charged on the item value, one on the amount presented to your payment method, and one on the currency conversion. Writing them as five symbols makes it obvious which unknown is worth chasing before you commit to a 300-unit basket.
| Symbol | Charged on | Where the figure would live | Value held here |
|---|---|---|---|
| S | Item subtotal, as listed at the moment of payment | The listing itself | Whatever your listing says |
| d | Domestic delivery from seller to warehouse | The listing or the order confirmation | Per seller; not fixed |
| s | Service charge, as a share or a flat per-order amount | The operator’s own published terms | No published figure held here |
| p | Payment processing, charged on the amount presented to your method | The operator’s terms, or your payment provider | No published figure held here |
| x | Conversion spread over the reference rate | The rate shown at checkout against a public reference rate | No published figure held here |
Two of the 5, S and d, are printed on the listing you pasted, so they are known before you pay. The other 3 are the ones people describe as hidden, and the accurate word is conditional: they are applied only when a condition holds, and the condition usually sits in a paragraph after the headline sentence.
Nothing on this page supplies a value for s, p or x, because none could be verified while writing it. A number copied from a forum post in March is not evidence about a checkout in October, and the correct request is 1 message asking the operator to state all 3 of them in writing, tied to your order number.
s, p and x are all recorded as no published figure on this site. Ask the operator and keep the reply; the arithmetic below works with any values you are given.
The formula, and why the order of the multipliers changes the total
If a flat per-order amount A also applies, the item-stage total is T = (S + d + A) × (1 + s) × (1 + p) × (1 + x). Written that way, each charge is applied to a running amount rather than to the original subtotal, and that is the whole reason the three cannot be added together and treated as one percentage.
The size of that effect is small on a small basket and grows with the base. Take 5%, 3% and 2% — placeholders for the arithmetic only. Added together they make 10 points, so a 300 base becomes 330.00. Applied in sequence, the same 300 base becomes 300 × 1.05 × 1.03 × 1.02 = 330.94, which is 0.94 more. On a 1,200 base the gap widens to about 3.8 units from the same three points.
- A spread applied to an already-converted number compounds twice, because it multiplies a running amount that includes the earlier charges
- A flat per-order charge behaves like a percentage that shrinks as the basket grows: 30 units is 10 points on 300, 5 points on 600 and 2.5 points on 1,200
- A minimum charge flips the ranking completely on small baskets, where it can exceed every percentage line combined
- A charge applied after conversion is exposed to the exchange rate on the day, so the same basket on two days pays two different totals
One practical consequence follows from the multiplication order alone: the last multiplier in the chain always costs most per point, because it acts on the largest running amount. That is why 1 point of spread is usually worth more attention than 1 point of service, even when the service number looks bigger on the page.
Substituting real positions: where each of the three lands
Put the placeholders into the formula with a 300 base, no flat fee, and see where the money goes. Service adds 15.00 to reach 315.00. Payment processing then adds 9.45, taking the running amount to 324.45. The spread adds 6.49 and the total settles at 330.94.
| Charge | Placeholder | Applied to | Amount added |
|---|---|---|---|
| Service | 5% | 300.00 | 15.00 |
| Payment processing | 3% | 315.00 | 9.45 |
| Conversion spread | 2% | 324.45 | 6.49 |
| Total | 10 points in sequence | Running amount | 30.94 |
Read the third column and the compounding becomes visible: the 2% that looks smallest adds 6.49, while a flat reading of 2% of 300 would add 6.00. The 0.49 difference is not a rounding artefact, it is the 9.45 of earlier charges being charged again at 2%.
That reframes the question to ask an operator. Instead of "what is your fee", ask which lines are charged on the item value, which are charged on the amount presented to the payment method, and whether anything is charged after conversion. Those 3 answers turn the formula from a template into a number that matches your own basket.
One extra point, priced three ways: reading the sensitivity
Move one variable at a time and the ranking appears. On a 300 base, an extra point of service adds 3.15, an extra point of payment processing adds 3.21, and an extra point of spread adds 3.24. On a 1,200 base the same three points cost 12.61, 12.85 and 12.98. The order never changes, and the spread stays the most expensive point in the chain.
| Variable raised by 1 point | Cost on a 300 base | Cost on a 1,200 base | Why it ranks there |
|---|---|---|---|
| Service (s) | 3.15 | 12.61 | Acts on the smallest running amount |
| Payment processing (p) | 3.21 | 12.85 | Acts on the subtotal after service |
| Conversion spread (x) | 3.24 | 12.98 | Acts last, on the largest running amount |
The number worth noticing is the ratio rather than the gap: on both bases, each point of any charge costs about 1% of the base, so the three unknowns together land near their sum in points. Ten points of unknown charges on a 1,200 basket came to 123.76 in the sequence above, against 120 if the same ten points were added, and that 124-ish figure is the one to hold in mind when a checkout total surprises you.
Three questions, 1 message, and a written reply will pin all of it down: what each charge is applied to, whether anything is charged after conversion, and whether a minimum applies per order. Comparing a small basket quote against a large one then reveals which lines are flat and which are proportional, without anyone having to publish a rate. The [fx-converter](/rig/fx-converter/) rig keeps the conversion leg separate, and the [pay-domestic](/steps/pay-domestic/) step marks the point where those 3 charges land on an order. The [cost](/table/cost/) page carries the longer list of lines seen across operators.
Adding 1 point to the service charge and 1 point to the spread on the 300 base gives 300 × 1.06 × 1.03 × 1.03 = 337.37 against 330.94, so those 2 points cost 6.43 where the two separate figures added to 6.39. The direction never reverses: the more points stack up, the more each later one costs, which is why asking for all 3 numbers in 1 message beats asking for them 1 at a time.
Quote the same three questions on a small basket and a large one. A flat charge stays put; a proportional one moves — and that comparison is yours, not a published rate.
Worked example: 5%, 3% and 2% applied in sequence to a 300 base gives 330.94, against 330.00 if the same ten points are simply added. One extra point costs 3.15 on the first multiplier and 3.24 on the last; on a 1,200 base the same point costs 12.61 to 12.98. The percentages are placeholders chosen for the arithmetic, not quoted rates.
This note explains the mechanics; the list is where the items are.