USD to THB for business payments

The Thai baht at a glance

The Thai baht (THB) is issued by the Bank of Thailand (BOT), the central bank. The BOT describes its regime directly: Thailand has operated under a managed float exchange rate regime since 2 July 1997. The baht is determined by market forces, the BOT does not target a specific exchange rate or peg the baht to any foreign currency, and it may intervene when the baht experiences excessive volatility. For a buyer, a baht invoice therefore carries exchange rate risk between order and payment.

Sources: BOT, Foreign Exchange Market; BOT, Exchange control regulation. Checked on 29 October 2026.

Thai exchange control rules that affect your payment

Thailand still has exchange controls, set by the BOT and summarized in its exchange control regulation. Four rules matter when you pay a Thai supplier.

• Repatriation. A person receiving foreign currency from abroad worth USD 1 million or more must repatriate it within 360 days from the export date or the transaction date, then sell it to an authorized bank or deposit it in a foreign currency account with an authorized bank within 360 days of receipt.
• FCD accounts. Thai residents may deposit foreign currency received from abroad into an FCD account without limit, and withdraw it to pay persons abroad or convert it when they choose. A supplier can therefore take your dollars without converting them.
• Baht for non-residents. Non-residents may open baht accounts with authorized banks: an NRBA, which may be used for general purposes such as trade, services and direct investment, and an NRBS, for investment in Thai securities.
• Baht against foreign currency abroad. The BOT lists payments related to the purchase or sale of foreign currencies against baht among the purposes that need its prior approval.

A foreign company without an NRBA does not hold baht itself. It pays a baht invoice through a provider that converts dollars and pays the supplier as a domestic transfer. Our guide to paying suppliers in Thailand covers this corridor in detail.

How a THB payment reaches a Thai supplier

A baht payout travels on Thai domestic rails. PromptPay is the instant payment service; Standard Chartered's guide states that it runs 24x7 and allows instant payments of up to 2 million baht, and a business can receive PromptPay payments to its 13-digit Tax ID instead of an account number, with only one Tax ID registered to one bank account, according to Bangkok Bank. SMART is the bulk credit service with same-day and next-day options. BAHTNET, the BOT's high-value system, settles each payment in real time, final and irrevocable, on bank working days from 8:30 a.m.

Sources: BOT, BAHTNET; Standard Chartered, Thailand PromptPay user guide; Bangkok Bank, BizPromptPay FAQ and BIZ iBanking fees; KBank, fees for FCD deposit and withdrawal. Checked on 29 October 2026.

For any route, get the account name, the account number for the invoice currency, the bank, branch and SWIFT code, and the supplier's 13-digit Tax ID in writing.

What converting USD to THB costs

A dollar to baht conversion is priced from the mid-market rate, the midpoint between buying and selling prices at that moment. Your provider adds a margin, the gap between that rate and the one you get, and charges a fee for the payment. On a $20,000 payment, a rate 1% below the mid-market rate costs $200, far more than most transfer fees. If you send dollars instead, the conversion moves to the supplier's bank, which converts on arrival unless the supplier holds an FCD account.

Helm is a financial technology company, not a bank. Its US dollar account services are provided by Bridge Building, Inc. (NMLS ID 2450917), a licensed money transmitter, with customer funds held at Lead Bank. A Helm account holds dollars in your company's own name and sends international payments to suppliers by SWIFT, or by local rails in the supplier's currency where available, with the rate, fee and expected arrival shown before you send.

Helm agrees pricing with each business in writing before the account opens, and shows the rate, the fee and the expected arrival before you confirm each payment. See how Helm pricing works.

Pay a Thai supplier in USD or THB?

• Pay THB when the supplier invoices in baht. Most of a Thai manufacturer's costs are in baht, so a baht invoice removes conversion from its side and can support a sharper price. You take the exchange rate risk.
• Pay USD when the invoice is in dollars and the supplier gives you an FCD account number. The supplier carries the rate risk and can hold the dollars to buy imported materials.
• Avoid dollars to a baht account. The supplier's bank converts on arrival at its own rate, and the invoice can end up short.
• Use BAHTNET for large baht amounts. A PromptPay payout above 2 million baht exceeds the instant payment limit cited above.

Thai exporters that receive dollars should read our guide to USD business accounts in Thailand.

Questions

References

1. Bank of Thailand: Foreign Exchange Market (exchange rate regime)
2. Bank of Thailand: Exchange control regulation
3. Bank of Thailand: BAHTNET systems
4. Standard Chartered: Thailand PromptPay user guide
5. Bangkok Bank: BizPromptPay FAQ
6. Bangkok Bank: BIZ iBanking fees
7. KBank: Fees for foreign currency deposit and withdrawal

This guide is general information for businesses, not financial, legal or tax advice. Rules, fees and timings were checked against the sources listed on the review date and may change.