Mollie

Connect your Mollie account to PayLexer.

Mollie is a European payment service provider headquartered in the Netherlands, trusted by over 250,000 businesses. It supports a wide range of local and global payment methods including iDEAL, Bancontact, SOFORT, SEPA Direct Debit, credit and debit cards, Apple Pay, Google Pay, PayPal, and Klarna, making it a strong choice for businesses targeting European customers.

Supported Regions (Merchant Accounts): Most European countries including Netherlands, Belgium, Germany, France, United Kingdom, Spain, Italy, Austria, Switzerland, and more - view full list
Supported Currencies: EUR, GBP, USD, CHF, DKK, NOK, SEK, PLN, and more

Supported Features

One-time card payments via Visa, Mastercard, and American Express
Webhook notifications for real-time payment status updates
Test mode for safe sandbox testing without real transactions
Multi-currency support across EUR, GBP, USD, and more

Before You Start

Make sure you have:

Mollie Account – Don't have one? Sign up for Mollie →
PayLexer Account – Required to configure the integration. Create your account →
A website where you want to integrate

Looking for a different payment processor? View all supported gateways →

Configuring Mollie

You need a Live API Key and Test API Key from Mollie for this integration.

Getting API Credentials

Go to my.mollie.com/dashboard and sign in to your account.

Open the Developers section

At the bottom of the left sidebar, click Developers, then click API access tokens.

Mollie dashboard showing the Developers link at the bottom of the left sidebar

Create an access token

In the top right corner, click Create access token. Enter a Description (such as "PayLexer"), select Standard API key as the token type, choose your Profile, and select Live mode or Test mode. Click Create access token.

You need to create two separate access tokens - one with Live mode selected and one with Test mode selected. Repeat this step for each mode.

Mollie API access tokens page with the Create access token button in the top right corner

Create access token form showing Description, token type, Profile, and Live mode or Test mode selector

Copy your API key

After the token is created, your API key is displayed once - you will not be able to see it again. Click the copy icon to save it before navigating away.

Repeat steps 3 and 4 twice: once with Live mode selected (your Live API key) and once with Test mode selected (your Test API key).

Your Live API key starts with live_ and your Test API key starts with test_.

Newly created access token displayed once with the copy icon highlighted - this is the only time the key is shown

Adding Credentials to PayLexer

Open PayLexer Dashboard

PayLexer Payment Gateways page with the Mollie gateway card highlighted and a Configure button

Enter your credentials

In the Live/Production Credentials section, paste your Mollie Live API key into the API Key field. In the Test/Sandbox Credentials section, paste your Mollie Test API key into the API Key field.

PayLexer Configure Mollie page showing the Live/Production Credentials and Test/Sandbox Credentials sections with API Key fields

Understanding Live/Production and Sandbox Settings:

Environment	Purpose
Live / Production (Mandatory)	Used for real transactions. Cannot be empty, even when testing.
Test / Sandbox (Optional)	Used for testing only. No real money is processed.

How PayLexer selects credentials:

Debug/Test mode ON → Test credentials are used
Debug/Test mode OFF → Live credentials are used

Save your configuration

Click Test Connection to verify each set of credentials, then click Save to store your configuration.

Your Mollie credentials are now saved in PayLexer.

Configuring Webhooks (Mandatory)

Webhooks enable real-time payment updates and significantly improve reliability.

Benefits of Webhooks:

Instant payment status updates when payments succeed or fail
Real-time notifications for refunds and chargebacks
Reliable order synchronization without depending on the customer returning through the redirect

Copy your PayLexer Webhook URL

In your PayLexer dashboard, go to Payment Gateways → Mollie and click Copy next to the Webhook URL shown in the Webhook Configuration section.

PayLexer Configure Mollie page showing the Webhook Configuration section with the Webhook URL and a Copy button

Add the Webhook URL in Mollie

Go to Developers → Webhooks and click Create webhook. Enter a Name, paste the Webhook URL you copied into the Webhook URL field, and select the payment events to listen to. Click Create to save.

Mollie webhook form showing the Name field, Webhook URL field with the PayLexer URL pasted, Payload style, and Event types selections

If you use the Mollie Dashboard to inspect individual payments, you will see the webhook URL listed under each payment's details. This is expected behavior.

Copy the Webhook ID and save to PayLexer

From Developers → Webhooks, click on the webhook you just created to view its details. Click the copy icon next to the Webhook ID to copy it.

Mollie Developers Webhooks page showing the PayLexer webhook with its status, Webhook ID, and Webhook URL

Mollie Webhooks page with the copy icon next to the Webhook ID highlighted

Then go back to Payment Gateways → Mollie in your PayLexer dashboard and paste the Webhook ID into the Webhook Secret field.

Integrate Mollie to Your Website

If you have already added and configured your site, you can enable Mollie in your existing setup.

Go to Websites

Navigate to Websites in your PayLexer dashboard.

PayLexer Websites page showing a listed website with the edit icon highlighted

Edit your website

Click the Edit Icon of your added website.

Enable Mollie

Click the checkbox to enable Mollie for the website, then click Save Settings.

PayLexer Edit Website modal with the Mollie checkbox selected and the Save Settings button highlighted

Run a test transaction in Test Mode before going live. See Test Transactions for instructions.

If you haven't added a website yet, Continue to Add Your Website →

Troubleshooting

Confirm you copied the correct key type - Live keys start with live_ and Test keys start with test_
Make sure there are no extra spaces before or after the key when pasting
Check that your Mollie account is fully verified and active; unverified accounts may have restricted API access
Re-generate the API key in your Mollie dashboard and update PayLexer with the new value

Verify the Webhook URL copied from PayLexer was not modified when saving
Ensure your website is publicly accessible - Mollie cannot reach a localhost or staging environment that is not publicly reachable
Check your server firewall and hosting settings to confirm inbound POST requests to the webhook URL are not blocked
Review Mollie's payment details in my.mollie.com to see if webhook delivery attempts are listed and their status

Confirm webhooks are configured correctly using the steps above
In Test Mode, use only Mollie test payment details - real card numbers are rejected
Check the PayLexer transaction log for any error messages returned from Mollie
If the issue persists in Live Mode, verify that the Live API key is saved (not the Test key) and that Test Mode is turned off in PayLexer

Mollie activates payment methods per-profile. Log in to your Mollie dashboard and go to Settings → Website profiles to check which methods are enabled for your profile
Some methods (such as Klarna and SEPA Direct Debit) require additional Mollie approval before they become available
The currency of the transaction must be supported by the chosen payment method

Best Practices

Always test the full payment flow in Test Mode before switching to Live credentials
Enable webhooks - without them, order status updates depend on the customer returning to your site, which is unreliable
Store your Live and Test API keys securely and never expose them in client-side code or public repositories
Keep your Mollie account profile up to date; outdated business information can trigger payment holds
Review Mollie's payment method availability in your target markets before launch - not all methods are available in every country
Enable only the payment methods your customers actually use to keep checkout clean and conversion high

FAQs

Live credentials are mandatory to save the configuration. Test credentials are optional but highly recommended so you can safely test payments before going live.

Check the Debug Mode setting in your platform. When Debug Mode is ON, PayLexer uses your Test credentials. When OFF, it uses Live credentials.

Transactions appear in three places: your platform's booking or order pages, PayLexer Dashboard → Orders, and Mollie Dashboard. All three show the same transactions with different IDs.

Payments will still process, but status updates may be delayed. Check webhook logs in Mollie Dashboard to troubleshoot.

Mollie is available across most of Europe, including the Netherlands, Belgium, Germany, France, the United Kingdom, Spain, Italy, Austria, Switzerland, Poland, and more. For the full list, visit Mollie's supported countries page.

Mollie supports EUR, GBP, USD, CHF, DKK, NOK, SEK, PLN, and several other currencies depending on the payment method. EUR is the primary currency and has the broadest method support.

Yes. Mollie requires you to create a separate access token for each mode. Create one token with Live mode selected and another with Test mode selected. Enter both in PayLexer so you can switch between modes without updating credentials each time.

Yes. Mollie supports recurring payments via SEPA Direct Debit and credit card mandates. Contact Mollie Support to confirm your account is enabled for subscriptions before relying on this feature.

iDEAL is available to Mollie accounts registered for Dutch transactions. If your account is registered in another country, check your Mollie website profile settings to confirm iDEAL is activated.

Mollie typically settles funds within 2 business days for card payments. Local methods like iDEAL and Bancontact may settle faster. Check your Mollie dashboard under Finances → Settlements for your specific settlement schedule.

Still Have Questions?

Mollie Support: Mollie Help Center
PayLexer Support: Contact Support

For API references and advanced configuration, see the Mollie developer documentation.

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