01 / START WITH THE WHOLE JOURNEY
The invoice price is one part of the budget.
Before comparing suppliers, ask what it will take to bring the goods to your delivery point. A lower product price can come with more transport or handling costs. Compare quotations on the same scope, currency and delivery basis.
| Cost component | What to clarify |
|---|---|
| Goods | The product total, quantity, price basis and currency. Check whether the amount is per piece, carton or the whole order. |
| Transport and insurance | Which legs of the journey are covered, who pays and whether amounts are already included in the supplier’s invoice. |
| Import duty and taxes | The classification, customs value, origin treatment and taxes applicable to the goods. |
| Clearance and local services | Brokerage, handling and onward delivery. Ask for the scope and any exclusions in writing. |
| Conditional charges | Possible storage, waiting, inspection-related handling or container charges. Ask when they apply and what could trigger them. |
Keep tax estimates separate from the logistics quotation. That makes it easier to see whether a change comes from the shipment’s tax treatment or the transport and service arrangements.
02 / THE TAX CALCULATION BASE
Customs value is not the tax you pay.
Customs value is the value used in assessing applicable duties and taxes. Thailand’s valuation system normally starts with transaction value, subject to the relevant conditions and adjustments. Where that method cannot be used, other valuation methods apply. Thai Customs: valuation ↓
For a straightforward import example, cost, insurance and freight to the place of import form the familiar CIF basis. This is a calculation basis—not an extra invoice to pay on top of the goods and transport.
Provide what you are paying, the currency and the included or separate shipment costs. You do not need to invent a customs value. The estimate can be built from those details, with any necessary adjustments identified for review.
Tell the team about unusual arrangements such as free-of-charge goods, related-party purchases or payments outside the invoice. A zero invoice amount does not, by itself, establish a zero customs value.
03 / COUNT EACH COST ONCE
Find out what the price includes.
Share the agreed delivery term and named place alongside the invoice. Then confirm the actual cost breakdown. A three-letter term is useful context, but the estimate also needs to know which charges are included in the amount entered.
If freight or insurance is included
Mark it as included. Do not add the same amount again as a separate charge. Keep the invoice or quotation that explains the inclusion.
If it is quoted separately
Provide the amount and currency, and describe the part of the journey it covers. A door-delivery quotation may combine several services; ask for clarification if you cannot separate them.
If the amount is not known yet
Identify it as missing or provisional. Do not enter zero merely to complete a form. An estimate based on an assumption should show that assumption so it can be updated later.
04 / KEEP THE CONVERSION CLEAR
The customs rate and your bank rate can differ.
Customs value is declared in Thai baht. The Customs Department publishes exchange rates, including separate import and export rates; use the applicable import rate for the relevant declaration date. A planning estimate made earlier may therefore change. Customs exchange-rate guidance ↓
Keep the original invoice currency in your records. For your cash budget, also consider what your bank actually charges to pay the supplier. That payment conversion and the customs conversion serve different purposes.
Check the quoted currency unit as well as the rate. Some currencies are listed per 100 units. Do not treat every published number as the value of one unit.
05 / FOLLOW THE NUMBERS
A simple duty and VAT example.
Assume goods cost THB 90,000, freight to import is THB 9,000 and insurance is THB 1,000. These are separate costs. Assume 10% duty and 7% VAT, with no excise, other taxes, relief or additional valuation adjustments.
Illustrative amounts, not a product quotation
- Goods + freight + insurance
- THB 100,000.00
- Customs value × 10% duty
- THB 10,000.00
- VAT base: value + duty
- THB 110,000.00
- VAT base × 7%
- THB 7,700.00
- Import duty + VAT
- THB 17,700.00
- Goods, freight, insurance and these taxes
- THB 117,700.00
Local services and other charges are excluded. The duty rate is hypothetical; check the actual rates and treatment for your goods and import date.
In this simplified case VAT is calculated on customs value plus duty. Some goods involve other taxes or charges that also affect the VAT base, so the simple formula is not universal. Official calculation references ↓
The THB 100,000 customs value is not added a second time: it already represents the goods, freight and insurance in this example.
06 / GET A MORE USEFUL ESTIMATE
Bring the numbers and their context.
- Describe each product. Include material, function, model and country of manufacture where known.
- Explain the price. Give the currency, quantity and unit. State whether the amount is a unit price or product total.
- Identify included costs. Supply delivery terms and any separate freight, insurance or other shipment amounts.
- Share supporting evidence. Include the invoice, packing list and available licences or origin documents.
- Set the delivery scope. Give the route, expected date and final delivery point for the logistics quotation.
A duty estimate is a planning figure. Read its assumptions and unresolved items alongside the result. The final declaration and logistics charges require their own confirmation.
Discuss duty & tax planning ↗07 / COMMON QUESTIONS
Before you finalise the budget.
Does zero duty mean no VAT?
Not necessarily. Duty and VAT are separate. Check the VAT treatment even if a preferential duty rate applies.
Why does the final amount differ from my estimate?
Review changed quantities, prices, exchange rates, classification, origin evidence and actual shipment charges. Compare the assumptions first.
Is a tax estimate the full delivered price?
No. Add the agreed logistics and local service costs, without duplicating amounts already included elsewhere.
Can I compare two quotations by their totals alone?
Check that both cover the same services, destination, tax basis and exclusions. Ask what remains payable separately and when the quotation expires.
Build a cost plan you can follow.
Send the commercial details and your delivery requirements. We can help separate the tax estimate from the logistics scope and identify the figures still needed.
Discuss your import costs ↗Understand preferential duty and Form E ↗Official references
General planning guidance, updated 12 September 2026. Examples use stated assumptions; actual treatment depends on the goods and import date. References open in a new tab.