A simple method to separate real costs, platform fees, target profit margins and invoice records.
1. List real unit costs
A selling price should reflect more than the cost of materials. Include time, packaging, external services, and other costs incurred for each project or unit sold. If you have shared overhead, decide how to allocate it fairly. Missing a meaningful cost can turn a seemingly profitable offer into a loss.
2. Do not confuse margin with markup
Markup is calculated from costs, while margin is measured against the selling price. They are not interchangeable. For example, with 30 CHF in unit cost, 25% target margin and 5% platform fees applied to the pre-tax selling price, the estimated pre-tax price is 30 ÷ (1 − 0.25 − 0.05) = 42.86 CHF. That leaves about 2.14 CHF for fees and 10.71 CHF in margin before any omitted costs.
3. Confirm how payment fees are charged
Check whether your provider calculates fees on the pre-tax amount, the full checkout total, or as a combination of percentage and fixed charges. The BY-R calculator explicitly assumes percentage fees on the pre-tax selling price. Adjust your own calculations whenever a processor uses a different basis.
4. Apply tax only when appropriate
Never assume a tax rate is applicable simply because it appears in an online example. Confirm registration and invoicing obligations through the relevant official guidance. For mathematical illustration only, a hypothetical 8% tax on 42.86 CHF adds approximately 3.43 CHF, making a total of 46.29 CHF. This example is not a statement of a current tax rate.
5. Make invoices clear and traceable
Before sending an invoice, review the issuer and customer details, invoice number, dates, service descriptions, quantities and totals. Add the identifiers and tax details legally required for the specific situation. Keep a copy of the invoice you sent and any supporting documents. A generic invoice template does not certify compliance.
6. Keep dependable backups
Save pricing scenarios and invoice drafts in a clear structure. Local tools with JSON backups can make it easier to recover data without requiring a complicated subscription service. Retain final PDF invoices and supporting records separately so you can explain a price or payment request later.
Practical BY-R Digital tools
General information only, not legal, tax or accounting advice.