Terms of Service

The Korean version of these terms is authoritative.

Effective date: 2026-12-09 (announced 2026-11-08)

1. Purpose

These terms govern the use of the K-OTP service (the website k-otp.dev, the console app.k-otp.dev, the API api.k-otp.dev, and related services; the "Service") provided by 1990Company (the "Company").

2. Definitions

  1. "Customer" means an individual or entity that agrees to these terms and uses the Service.
  2. "End user" means a person who receives a verification code at the Customer's request.
  3. "API key" means a credential for calling the Service: a browser public key (pk_) or a server secret key (sk_).
  4. "Credits" means prepaid units used for paid features such as issuing codes.
  5. "Template" means a pre-registered message text used for verification messages.

3. Changes to these terms

The Company posts these terms on the Service and may amend them within the limits of applicable law, announcing the effective date and reason at least 7 days in advance (30 days for changes unfavorable to Customers). Customers who do not agree may terminate their agreement.

4. The Service

OTP generation, delivery over KakaoTalk AlimTalk and SMS, and verification APIs; delivery status, issue history, and credit ledger APIs; console features such as API key management and credit top-ups.

5. Accounts and API keys

Customers must keep account credentials and API keys safe. Secret keys (sk_) must stay on servers. Public keys (pk_) work only from Origins the Customer registers. Revoke a key immediately and notify us if it may have leaked.

6. Customer obligations

Customers must not send codes without the end user's request or consent, send advertising, violate Korean laws such as the Network Act, Telecommunications Business Act, or Personal Information Protection Act, misuse third-party phone numbers, disrupt the Service, attempt to bypass authentication, or obtain or use free credits (section 7) improperly, such as by creating multiple accounts or signing up with a disposable (temporary) email address.

7. Credits

Credits are prepaid. Each OTP send uses 1 credit regardless of channel (AlimTalk, SMS, or automatic SMS failover after an AlimTalk failure); packs and prices are listed on the pricing page. Korean won (KRW) prices exclude value-added tax: 10% VAT is added at checkout and the amount charged includes it (e.g. Starter ₩27,000 + ₩2,700 VAT = ₩29,700). US dollar (USD) prices exclude applicable taxes; Creem (section 7A) calculates them for your location and adds them at checkout, and the total is shown before you pay. Issuing a code reserves 1 credit; the reservation is debited once the send is accepted and released if queueing or sending fails. Retries with the same idempotency key and payload are not charged again. Requests are rejected when the balance is insufficient. Credits purchased with a payment do not expire. Credits the Company grants for free, such as the signup bonus and referral rewards ("free credits"), can be used for 1 year from the grant and then expire; they are used before purchased credits (soonest expiry first) and are not refundable. Free credits are granted under the conditions the Company sets: the Company may withhold them, or grant them only after a review, for example when the same Customer or email address has already received them or the account was registered with a disposable (temporary) email address. The Company may reclaim remaining free credits obtained or used by improper means (including the conduct described at the end of section 6); referral rewards follow the Referral Program Terms. Refunds follow the Refund Policy.

7A. Payment processing

USD payments for credits are processed by Armitage Labs OÜ (registry code 16977866, Estonia), trading as Creem ("Creem"), as the merchant of record. The purchase transaction for a USD payment is subject to Creem's Buyer Terms, including the governing law and jurisdiction they set (the laws of the Republic of Estonia and the Harju County Court in Estonia); the use of credits and of the Service is governed by these terms, and disputes about it follow section 11. Creem issues the receipt and invoice for a USD payment and calculates, collects and remits the taxes (such as VAT) that apply to it. The Company remains responsible for providing the credits and the Service and for customer support, which you can reach at support@k-otp.dev. Refunds of USD payments are made by Creem at the Company's request under the Refund Policy. Orders paid through Polar before the switch to Creem are handled by Polar and refunded through Polar under the Refund Policy.

Credits paid for by Korean card in KRW are sold by the Company; the payment is processed by the payment agent Creb Co., Ltd. ("Creb"). Creem's Buyer Terms do not apply to KRW payments; these terms and the Refund Policy do. The receipt for a KRW payment is the card slip issued with the card payment, and the Company files and pays the VAT. The payment window requires the buyer's name and mobile phone number, which the Company does not store. Payment limits (per payment, per day, per month) are set by Creb, and a payment above them may not be approved.

8. Changes and interruptions

The Company may change the Service for operational or technical reasons, announcing material changes in advance, and may suspend it temporarily for maintenance, outages, or force majeure.

9. Limitation of liability

Absent intent or gross negligence, the Company is not liable for non-delivery or delay caused by carriers, messaging providers such as Kakao, or end-user devices. When a delivery outcome is ambiguous, the Company does not resend automatically, to avoid duplicates. Except in cases of the Company's intent or gross negligence, the Company's liability for damages in connection with the Service is limited to the amount the Customer paid for the Service (including payments made through a payment provider or merchant of record) in the 3 months before the date the damage occurred.

10. Termination

Customers may terminate at any time. The Company may restrict or terminate use after notice if a Customer breaches section 6.

11. Governing law and jurisdiction

These terms are governed by the laws of the Republic of Korea. Lawsuits regarding disputes over the Service are brought before the court with jurisdiction under the Civil Procedure Act of the Republic of Korea. This section does not apply to USD purchase transactions with Creem, which follow Creem's Buyer Terms under section 7A.

Effective date

  1. These terms take effect on 2026-12-09.
  2. Until then, the previous terms (effective 2026-10-14) apply.

Change history

  • Announced 2026-11-08, effective 2026-12-09: to prevent free credits from being obtained improperly, the following changed. Because the change may be unfavorable to Customers, it was announced 30 days before it takes effect.
    • Section 6: obtaining or using free credits improperly, such as by creating multiple accounts or signing up with a disposable (temporary) email address, is now prohibited conduct, to which section 10 (restriction and termination after notice) applies.
    • Section 7: free credits are granted under the conditions the Company sets, and the Company may withhold them, or grant them only after a review, for example when the same Customer or email address has already received them or the account was registered with a disposable (temporary) email address. The previous terms set no conditions for free credits. The reclaim sentence now states that "improper means" includes the conduct added to section 6.
    • No other provision (prices, purchased credits, the validity of free credits, refunds) changed.
  • Effective 2026-10-14 (KRW card payments): because a KRW card payment option through the payment agent Creb was added, the following changed. The amendment adds a payment option and does not change existing customers' rights or prices, so the Company published it on 2026-10-14 without a prior notice period.
    • Section 7A: a second paragraph states that KRW card payments are sold by the Company and processed by Creb, that Creem's Buyer Terms do not apply to them while these terms and the Refund Policy do, that the receipt is the card slip and the Company files and pays the VAT, that the buyer name and mobile phone number entered in the payment window are not stored by the Company, and that payment limits are set by Creb.
    • No other provision (Customers' rights, credit rules, prices) changed.
  • Effective 2026-10-14: the credit pack lineup changed (Mini, Starter and Scale), and only the price example in section 7 changed in these terms.
    • Section 7: the example of the VAT added to a KRW price now reads "Starter ₩27,000 + ₩2,700 VAT = ₩29,700" (it previously read "Starter ₩19,900 + ₩1,990 VAT = ₩21,890"). The packs and prices on the pricing page changed with it. The Company published the new packs and prices on 2026-10-14 without a prior notice period, because they apply only to purchases made from that day. Packs bought earlier keep the composition and the price they were sold with, and are refunded under that composition (see the Refund Policy).
    • No other provision (Customers' rights, credit rules) changed.
  • Effective 2026-10-07: because USD payments are now processed by Creem, the following changed. This amendment was first announced on 2026-10-06 to take effect on 2026-11-06 and announced again on 2026-10-07, with the USD tax sentence in section 7 added, to take effect on 2026-11-07; because there had been no actual USD purchases yet, it was brought into force on 2026-10-07.
    • Section 7A (Payment processing) was added. It states that Creem (Armitage Labs OÜ, Estonia) processes USD payments as the merchant of record, that the purchase transaction is subject to Creem's Buyer Terms and their governing law and jurisdiction (Estonian law, Harju County Court), that Creem issues receipts and invoices and handles taxes, that the Company remains responsible for the Service and customer support, and that orders paid earlier through Polar are handled by Polar. The previous terms had no provision on who processes payments.
    • Section 9 (Limitation of liability): the reference amount for the liability cap was reworded from "the amount the Customer paid the Company" to "the amount the Customer paid for the Service (including payments made through a payment provider or merchant of record)". The cap itself (payments in the 3 months before the damage) is unchanged.
    • Section 11 now states that it does not apply to USD purchase transactions with Creem, which follow Creem's Buyer Terms under section 7A. The governing law and jurisdiction of the service agreement with the Company did not change.
    • Section 7 (added 2026-10-07): a sentence states that USD prices exclude applicable taxes, which Creem calculates for your location and adds at checkout, showing the total before you pay. The previous terms only explained the VAT on KRW prices.
    • No other provision (Customers' rights, prices, credit rules) changed.
  • Effective 2026-10-03: previous terms.