Security Best Practices

Topics covered on this page

This document describes your responsibilities as a merchant when accepting payments online and best practices to meet them. It is a companion to our Security at Opn Payments document that introduces our organizational approach to security including important concepts such as tokens, encryption, and PCI DSS compliance.

Please read this document carefully. If there is anything you do not understand, please reach out to us.

Send Card Details from the Client Device

We are certified PCI DSS compliant. PCI DSS is a set of industry-mandated requirements that ensures that card details are processed, stored and transmitted in a secure environment.

To comply with these requirements, you are required to send card details directly from the user's client device to our encrypted vault server using one of our client-side libraries or plugins.

These libraries return one-time-use tokens that you use on your backend server to create charges and perform other card operations. Using tokens, actual card details never go through your servers.

Token overview

The only exception is for merchants who are themselves PCI DSS certified. PCI DSS certified merchants are still required to notify us if they are planning to handle card details directly.

If you are collecting payments on a user's browser, use Omise.js and its pre-built payment form. If you are collecting payments on a user's mobile phone, use our iOS or Android SDKs. If you are using a plugin, do not modify its source code.

Avoid Accidentally Capturing Sensitive Card Details

You should take steps to avoid accidentally capturing sensitive card details.

When building payment forms, ensure that form parameters containing card details are not inadvertently sent to your server or captured in server logs.

Disable tracking on your checkout page. Analytics tools such as Mixpanel and Google Analytics collect data on the page on which they are loaded, potentially including any sensitive details, and send that information to a third party.

Enable HTTPS on Your Website

HTTPS is required for your checkout page and highly recommended for your entire website.

Enabling HTTPS on your checkout page will protect your users' sensitive data, prevent account compromise, and inspire greater user confidence, which can lead to increased sales. Search engines rank HTTPS-enabled sites higher.

Transport Layer Security (TLS) is the successor to SSL. You are required to use TLS (at least version 1.2) and supported ciphers to enable HTTPS on your web servers.

We recommend using Let's Encrypt for your certificates.

HTTPS is also required for your webhook endpoint URL, if enabled.

Supported TLS Ciphers

We support the following TLS ciphers:


Other less secure TLS ciphers may not be supported.

Store and Transmit Secret Key Securely

Each account has a public and a secret key (see API Authentication). Your public key can only be used for limited, safe operations such as tokenizing credit cards.

Your secret key, however, can be used to perform all other API operations, such as creating charges, refunds, transfers, and downloading customer information. You should therefore take the following steps to keep your secret key secure:

  • Never commit your secret key on your code repository. Instead, use environment variables to store your secret key (see example documentation for Heroku)
  • Never share accounts. To see if someone else accessed your account, check
  • Always use strong passwords and Two-Factor Authentication (2FA) on your dashboard, website, and any other e-commerce administrative backend you use.

If you find that your secret key has been compromised, you are required to login to your dashboard account and roll your keys as soon as possible.

It is recommended that you notify us about the compromise early so we can verify your account security.

Follow Recommendations for Minimizing Fraud

Our fraud protection system requires detailed transaction data to calculate the risk score for given transaction.

In addition to providing a payment form and a secure way to collect credit card details, Omise.js also collects extra information such as the user's client IP, browser agent, and browser history used by our fraud protection system.

For example, if the IP belongs to a server hosting provider, Tor network or public proxy, the chances of fraud are high, but if the IP belongs to an ADSL user matching the country of the card issuer, it is most likely a legitimate transaction.

To get the most benefit from our automated fraud protection, it is recommended to capture billing address details, especially for customers from the United States and Canada, and provide recommended parameters such as charge.ip, charge.description, and

Supplying extra information about purchases (e.g. number of items, type of items, date of delivery) and customers (e.g. the customer's real IP address) feeds data into our fraud protection system, which makes it more accurate.

Monitor Your Logs

Some types of business are prone to fraud (see our list of explicitly prohibited businesses).

For example, services such as mobile top-up allow cash value to be extracted by a malicious actor before refunds or voids can occur.

If some aspect of your business falls into this category, we advise you keep a close eye on your logs for risky or fraudulent transactions. Login to your dashboard and click Logs.

Stay Updated

Security threats are constantly evolving, and so are we. We regularly release new versions of our libraries to eliminate bugs or potential vulnerabilities.

Keep your software updated, and check this page for up-to-date recommendations for securely accepting payments online.

Omise uses cookies to improve your overall site experience and collect information on your visits and browsing behavior. By continuing to browse our website, you agree to our Privacy Policy. Learn more