Calculate airtime resale margin per transaction
If a customer pays R50 and your supplier charges R49.50, you’ve earned 50 cents before fees and other costs. Start with a completed sale, then subtract the costs you can tie to it. The amount left is the sale’s contribution towards running the shop.
Per-sale worksheet
| Item | Hypothetical amount |
|---|---|
| Customer pays | R50.00 |
| Supplier cost | R49.50 |
| Gross earnings | R0.50 |
| Allocated payment cost | R0.10 |
| Contribution before overhead | R0.40 |
By Freepaid · Published
Use the right terms
Face value is the amount of prepaid value delivered to the customer. Supplier cost is what your business owes for the completed transaction under its terms. Customer payment is what the customer actually paid. Gross earnings per sale are customer payment less supplier cost. Contribution subtracts additional variable costs that can be assigned to that transaction.
Margin percentage and markup percentage use different denominators. If a retailer sells for R50 and pays R49.50, gross earnings are R0.50. The margin on customer sales is R0.50 ÷ R50 = 1%. The markup on supplier cost is R0.50 ÷ R49.50, approximately 1.01%. Label each percentage in your worksheet so nobody compares a margin on sales with a markup on cost.
Worked calculation
After the fee in the worksheet, the sale contributes R50.00 − R49.50 − R0.10 = R0.40. At 500 completed transactions during a month, contribution would be R200 (500 × R0.40), before rent allocation, staff overhead or taxes.
A simple worksheet formula is: (customer payment − supplier cost − transaction-specific charges) × completed quantity. Keep unresolved orders out of completed-sale totals until their outcomes are verified. Record reversals and credits separately and tie them back to original references rather than silently netting them against another day.
Where to get the costs
Use the dated supplier quote or transaction statement for cost, not a remembered discount. Confirm whether the price is calculated on face value and whether charges apply per order, account or funding event. For customer payment, use till receipts and actual settlement data. Include card or payment fees only when the method applies to the transaction.
Allocate staff minutes using observed time where possible. For example, if a cashier spends 30 seconds on each of 100 transactions, that is 50 minutes in total. To convert time to cost, use an approved internal labour rate and state it. Avoid dividing fixed rent by airtime sales without explaining why that allocation helps the decision.
Reconcile and review
Compare the worksheet with till receipts, supplier statements and bank or wallet records. Match each order by date, amount, product, internal reference and supplier reference. Investigate missing or duplicate records before calculating a monthly return. Update the worksheet when supplier terms change and preserve the effective date of each set of assumptions.
For accounting presentation and tax treatment, consult your accountant. Check Freepaid point-of-sale airtime for business context and ask the supplier for current commercial terms.
Combine sales with different values
Suppose ten confirmed R20 sales contribute R0.85 each and 20 confirmed R50 sales contribute R0.40 each. Combined contribution is R16.50 from R1,200 in customer payments, or about 1.38% before fixed costs. The R0.85 case could reflect a R18.80 supplier debit and R0.35 in per-sale costs. Use the total rand amounts for the percentage. An unweighted average of the two product margins would give the same weight to products that make up very different shares of sales.