Worked example · fictional data
A lower rate.
The same cost?
For the same 1,000 shipments, B’s known subtotal is CZK 6,000 lower. Unresolved costs could change that result.
The companies, documents and amounts are fictional. For this example, we assume both services meet the requirements. This is not a client result or a claim of realised savings.
What we know.
Breakdown of both subtotals
| Item | A | B |
|---|---|---|
| Shipping | CZK 85,000 | CZK 78,000 |
| Known surcharges | CZK 7,000 | CZK 7,000 |
| Returns | CZK 3,000 | CZK 4,000 |
| Internal handling | CZK 5,000 | CZK 5,000 |
| Known subtotal | CZK 100,000 | CZK 94,000 |
Surcharges are separate from shipping. Both options assume the same number of returns. Handling is 10 hours × CZK 500 in each option: an allocated capacity cost, not automatically cash saved. None of the listed items overlap.
The break-even point
CZK 6,000.
B’s remaining costs can exceed A’s by this much before their total costs for the month become equal.
X = unresolved costs for B minus those for A over the same period. Total difference B − A = −6,000 + X. Zero is only a scenario, never a substitute for missing information.
Check the open costs before deciding.
Obtain written confirmation of unclear charges and check changes to the work with the operations team. Count a one-off transition cost once within the chosen time horizon; show recurring costs separately.
B has the lower known subtotal. We do not yet recommend changing carrier. If the unresolved net difference is below CZK 6,000 and the services meet the requirements, B remains cheaper in this monthly model. Otherwise, the conclusion changes.
The break-even point does not establish the probability of a saving, an annual saving or a reason to disregard service quality.
How do your offers compare?
Use your own inputs and keep unresolved costs explicit.
Sources, use and limitations
An original Brief & Field application. The sources help frame the approach; they do not validate this tool’s accuracy or predict your business results.
- The AQuA Book — an analytical quality framework covering calculation checks, model suitability, data, assumptions and uncertainty. Sections reviewed: 6.1–6.4, 8.2.1–8.2.2 and 8.3–8.4. This is not experimental validation of this calculator; the shipping categories and worked example are ours.
- Dopravio — an example of existing software for assigning carriers and comparing invoices with contracts. Sections reviewed: “Objednávka → dopravca”, “Faktúra vs zmluva” and the FAQs on required data and contract-reading errors. This is the supplier’s description, not independent evidence of effectiveness; we have not tested the product.
Your existing platform, carrier support or an available tool may handle a routine comparison. Check that option before commissioning individual work.
This comparison is not a universal tariff calculator. Contract rules and service suitability need specific checks. Do not annualise one month without checking the future shipment mix. Do not assign a value to lost revenue or reputation without supporting evidence. A corrected invoice, a modelled alternative and a realised saving are different outcomes; count each cost only once.
Our original methods, worksheets and annotations: CC BY 4.0. Credit Brief & Field, link to the original guide and identify your changes. The licence excludes trademarks, illustrations, fonts and third-party publications. Public access to a third-party source does not confer permission to republish it. Citing these sources does not imply institutional endorsement or affiliation.