Payletter

Payletter Payment Gateway Overview For Merchants

Payletter is a South Korea based payment service provider that offers payment gateway services for online merchants, with product lines that cover domestic payments in Korea and overseas payment acceptance for cross-border commerce. In addition to standard card processing, Payletter supports a broad set of local payment methods, including mobile phone billing, bank transfer, virtual accounts, vouchers, prepaid instruments, and multiple wallet style options.

Payletter Payment Gateway At A Glance

Payletter Inc. was founded in 2001 and is headquartered in Seoul, Republic of Korea.

Payletter’s payment gateway services are presented under the PayOneQ brand and include:

• Domestic Payment Service for Korea-focused acceptance

• Overseas Payment Service for international methods and currencies

• Payletter Easy-Payment Service for stored payment experiences tied to a merchant’s member base

• Developer documentation and API reference for gateway integration

• Merchant portals for domestic and overseas operations

Geographic Coverage And Typical Merchant Use Cases

Domestic Payments In Korea

For merchants selling online in Korea, Payletter supports a multi-method checkout model that includes cards, carrier billing, account based transfers, and voucher or prepaid flows. The domestic offering is framed for internet commerce, including digital content scenarios where teen-friendly or voucher methods can be important.

Overseas Payments For Cross-Border Commerce

Payletter’s overseas payment service is positioned for merchants that want to accept international payment methods, including global card brands and popular wallet or prepaid products in parts of Asia. Payletter also presents a service model that includes local currency approvals and foreign currency settlement options, with settlement handled on a contracted schedule.

Supported Payment Methods And Schemes

Domestic Payment Methods

Payletter’s domestic service lists a wide set of payment options that can be offered at checkout. The catalog includes:

• Cards and card-like payments

  • Credit card payments (credit and check card company coverage is described at a general level)

• Carrier and telecom billing

  • Mobile phone payments billed to the next month’s mobile phone bill

  • Phone bill payments (landline flow described via ARS and billing number entry)

• Bank transfer and account based methods

  • Bank transfer (real-time account transfer with certification based authentication)

  • Virtual account payments (payer deposits to an issued virtual account number)

• Wallet style and easy pay options

  • Payletter Easy-pay

  • Samsung Pay, Naver Pay, Kakao Pay, SSG PAY, PAYCO, Toss, CHECKPAY, Apple Pay

• Vouchers and prepaid

  • Voucher category and named instruments such as Culture Voucher, Book Voucher, Smart Culture Voucher, Teencash, Eggmoney, POSA Gift Card, and convenience store cash style flows

• Transportation card methods

  • Mobile T-Money and Mobile EZL

This breadth can be relevant for merchants targeting audiences that prefer non-card methods or need alternatives for specific demographics.

Overseas Payment Methods

For overseas acceptance, Payletter’s feature descriptions enumerate payment methods by category:

• Credit and debit card brands

  • Visa, Mastercard, American Express, UnionPay, JCB

• E-wallets

  • Alipay, PayPal, WeChat Pay, Razer Pay, WebMoney

• Prepaid and voucher style products

  • paysafecard, CHERRY Credits, NET CASH, MyCard, Razer Zgold

The overseas service also references an integrated API model for adding payment methods without additional development resources for each method.

Checkout Flows And Billing Options

Hosted Payment Page And Redirect Based Checkout

Payletter’s API documentation describes a model where a payment request results in URLs for a payment page (including separate online and mobile URLs). The payer completes the transaction in the Payletter payment flow and is returned via a return URL mechanism.

Server Notifications And Webhook-Like Callbacks

Payletter’s integration includes a callback URL mechanism that delivers payment results in JSON for successful payments. The documentation describes retry behavior for callback failures, including repeated attempts on a time schedule, and visibility of failed notifications through the merchant admin interface.

Recurring Payments And Stored Credentials

Payletter’s API reference includes recurring payment capability for certain methods, using a billing key concept for re-payments. This aligns with scenarios such as subscriptions, member billing, or repeat purchases where a merchant needs subsequent charges without repeated full checkout entry.

Operational Considerations For Settlement And Currencies

Currency Support For Overseas Payments

Payletter lists supported currencies for overseas processing as follows:

• Approval currencies: KRW, USD, CAD, JPY, EUR, TWD, VND, PHP

• Settlement currencies: KRW, USD, CAD, JPY

The materials note that available local currencies can vary by payment method, and the service is described as providing foreign currency settlement as well as local currency approvals.

Settlement Timing

Payletter’s payment gateway process pages state that settlement is made according to a contracted settlement period. This indicates settlement timing is program-specific rather than a single universal payout window.

Pricing Model And Public Fee Transparency

Payletter provides a Registration and Fee page that outlines categories of fees, including:

• Store registration fee

• Payment method registration fee

• Store ID adding fee

• Other miscellaneous items

However, the public materials do not publish a detailed fee table with numeric setup, monthly, or per-transaction pricing. The fee page indicates that amounts are guided by Payletter payment service personnel and paid through Payletter payment links.

Developer Experience And Integration Resources

One Integration For Multiple Methods

The domestic payment service describes an integrated API intended to enable multiple payment methods in one connection. It also highlights standardized integration that can adapt to business environment changes.

Documentation And Sample Code

Payletter provides a public API reference and includes sample source code references that cover common web stack environments such as ASP, ASP.NET, JSP, PHP, and Node.js.

Platform Environment Notes

Payletter’s domestic service page lists supported browser and OS environments, including Windows, macOS, and Linux, with modern browser families. This is relevant for merchant back-office access as well as testing in typical environments.

Security, Fraud Controls, And Compliance Posture

PCI DSS And Security Certifications

Payletter’s domestic payment service includes a PCI DSS certification section and references PCI DSS Level 1 certification in its security narrative. The API reference also describes a stable payment environment with PCI DSS and ISMS as part of its security certification positioning.

Data Protection And Integrity Controls

The domestic service content describes database encryption, real-time monitoring, and protection against data forgery, alteration, and loss using a TCP-IP socket interworking method. The API documentation also specifies an integrity mechanism using a SHA-256 hash value that must match a payhash parameter to protect return and callback parameters against forgery and falsification.

Fraud Prevention With FDS

Payletter describes operating its own Fraud Detection System (FDS) with scenario-based and AI-based detection. The same section indicates a model aligned with solutions used by financial institutions and card companies, with tuning intended to improve detection quality.

Merchant Portals, Reporting, And Support

Merchant Administration Portals

Payletter provides separate merchant administration portals for domestic and overseas merchants. A company notice about the manager page describes usability enhancements such as a transaction status card, a settlement calendar, and customizable menu shortcuts.

Reporting And Transaction Search

Payletter offers transaction search functionality as part of its support tools, and the API reference includes endpoints and mechanisms that support payment history search and operational monitoring, including visibility into failed callback notifications through the merchant admin page.

Support Channels

Payletter lists multiple support contact points, including a central telephone line and service emails. For payment gateway services, contact addresses are provided for domestic and overseas inquiries, alongside an online inquiry form.

Conclusion

Payletter is an online payment gateway provider with a Korea-centric domestic service that supports a wide set of local payment methods and an overseas service that bundles global card brands, wallets, and prepaid products under an integrated API model. Its documentation emphasizes hosted payment pages, callback notifications, recurring payment capability for certain methods, and merchant portals for operational management. From a security and risk standpoint, Payletter presents PCI DSS and ISMS positioning, integrity controls for payment notifications, and an AI and scenario-driven FDS framework.