PayPal PayPal Express Checkout whmcs
whmcs how to pay with paypal without registration
PayPal vs PayPal Express

PayPal Express Checkout

The PayPal Express checkout module allows your clients to check out in a single click without the need to enter their details into the WHMCS order form. The client's name, address, email and phone number will be taken from those stored in their PayPal account and a one-time payment sent when the Express Checkout button is clicked on the order form.


Begin by activating the payment gateway under Setup > Payments > Payment Gateways and choose PayPal from the Available Gateways dropdown.
Once activated, you can then enter the configuration details explained below. By default clients can chose between one-time and subscriptions payments and enter their own billing details on the PayPal site, the following options allow this behaviour to be changed.
PayPal Email

Enter the email address associated with your PayPal account, this is the only required field and all others are optional. If you have more than one email address associated with your PayPal account, you may add as many of those as you like, comma-delimited. You must next configure Instant Payment Notifications.
Force One Time Payments

When ticked clients will only be able to make one-time payments (subscriptions disabled). For recurring services they will be required to login and pay each invoice.
Force Subscriptions

When enabled clients will only be able to make subscription payments when applicable (one-time payments disabled). This means future payments will be sent automatically without the need for manual intervention. There are some caveats explained below.
Require Shipping Address

Ticking this option will require clients to provide a shipping address on the PayPal website and will be associated with their payment at PayPal, useful when selling physical products and for PayPal's Seller Protection.
Client Address Matching

The details the client provides in WHMCS upon ordering (name, address, phone number etc) will be used associated with their payment at PayPal, they will not be given the opportunity to provide different details on the PayPal website. Clients can update their profile via the WHMCS client area, your staff can use the Profile tab.
API Fields

Used for issuing refunds within WHMCS (saving the need to login at PayPal).
These credentials can be accessed with the API Credentials tool found in the Tools > All Tools section of the PayPal Business dashboard. Alternatively, they can be accessed directly by navigating to
For more information refer to Automated Refunds
Instant Payment Notification (IPN)

PayPal IPN Setup

For PayPal invoices to be automatically marked paid when you receive a payment you need to enable IPN inside your PayPal account.

  1. Navigate to Profile > Profile and Settings > My Selling Tools > Instant Payment Notifications
  2. Click the Choose IPN Settings button
  3. Enter in your WHMCS System URL eg.
  4. Select the Enabled option
  5. Click Save

Charset Configuration

PayPal Charset Configuration

PayPal defaults the charset used for most accounts to windows-1252. Whilst this is acceptable and will not cause an issue for most users, on occasion, accented characters can be returned incorrectly through the IPN causing the IPN Handshake Invalid message. Setting the charset in your PayPal account to match your WHMCS installation is a recommended setting to ensure this issue does not occur. The default value is UTF-8.
This is done in Profile > My Selling Tools > PayPal button language encoding (at the very bottom of the page). Once here, click on More Options and choose your charset from the dropdown and ensure the radio option is set to Yes. Click on Save and your configuration is completed.
PayPal Subscriptions/Recurring Billing

Unless disabled in the PayPal gateway config, when a user views an invoice for a recurring product or service they will be shown a PayPal Subscribe button. This allows the user to subscribe so that their payment for that product or service is sent to you automatically each month/quarter/etc... and automatically applied to the appropriate renewal invoices by WHMCS.
There are three conditions that must be met for the PayPal subscribe button to appear:

  1. The invoice's Due Date must be in the future
  2. The invoice must contain at least 1 recurring product (ie. domains, billable items or addons on their own won't create subscriptions)
  3. The 'Force One Time Payments' option is UNticked on the payment gateway configuration page.

If an invoice contains both a product, and addons or domains, then any which match the products billing cycle will also be included as part of the subscription. For example, if an invoice contained a product, an addon & a domain, all of which recur on an annual basis, then the PayPal subscription that gets created by WHMCS would be for the total amount of all 3 items so that the subscription would cover everything and pay the renewal invoice in full automatically. What isn't possible however is to create a subscription that has different amounts recurring on different recurring terms, ie. $x Monthly + $Y Annually. PayPal doesn't offer an option for that at the current time.
Customising Invoice Emails for Subscriptions

When a subscription is created, the Subscription ID number that gets issued by PayPal is stored by WHMCS in the Subscription ID field for the product. Similarly when a subscription is cancelled the Subscription ID gets removed again. Therefore it is possible to use that ID value to determine if a subscription exists and therefore customise the text shown to the customer in the invoice related emails based on that.
For example, one might customise the "Invoice Created" email template to show different instructions to the customer if a subscription exists (meaning no manual action is required), compared with if one doesn't (meaning the client needs to login and pay the invoice manually), for example:
{if $invoice_subscription_id}
As you have a PayPal Subscription setup, payment will be taken automatically within the
next few days. Please ensure you have enough funds in your PayPal account to cover it.
You can login to your client area to view and pay the invoice at {$invoice_link}
Automated Refunds

You can issue refunds for PayPal payments directly from within WHMCS. Before you can do this however, you need to setup PayPal API access. The steps for doing this are as follows:

PayPal Refunds Step 1

  • Login to PayPal
  • Go to Profile > My Selling Tools > API Access
  • Click View API Signature - under the NVP/SOAP API integration heading
  • Choose Request API Signature - and click Agree and Submit

  • PayPal Refunds Step 2

  • Copy the username, password and signature that get provided and then click Done
  • Enter the details from the previous step into the WHMCS Payment Gateways config screen where requested

You will now be able to enter a refund and have it sent from PayPal at the same time from within the WHMCS admin area invoice management screen.

Error Messages

Invalid Receiver Email

WHMCS validates the payment receiver email value against the details specified under Setup > Payments > Payment Gateways so this error means the two do not match. If multiple PayPal accounts are used to receive payment, or a single PayPal account has multiple email addresses associated with it ,they must all be listed in a comma separated list eg. [email protected],[email protected].
The first email you specify will then be the email used for new payments, but any email in the field will be accepted as an invoice payment.
Not Supported

This Result will appear when an action occurs that does not require any action on WHMCS' behalf, for example a txn_type value of "subscr_failed" mean a subscription payment failed or "subscr_eot" means End of Subscription Term. You will see these entries under normal operation and is not a problem.
Unrecognised Currency

This error in the Gateway Log means an invalid currency code has been entered under Setup > Payments > Currencies. A currency code must use the ISO 4217 standard as explained on the Currencies page. For example EURO is not valid, but EUR is valid.
This could also be caused by a blank space at the beginning or end of the currency code, so edit the code to ensure there are none.
IPN Handshake Invalid

Getting this message in your Gateway Log would mean that WHMCS is unable to verify that the callback occurring has come from PayPal. This is to stop any false payments being applied to your account, however, on occasion, some valid payments can generate this error. Follow the instructions above for setting the Charset of your IPN to stop this.
IPN Handshake Error

Getting this message in your Gateway Log indicates that whilst the IPN from PayPal was received, WHMCS was unable to verify the IPN data. The verification process involves connecting to PayPal's callback verification service at This error will be observed if that connection fails. It can fail if the cURL connection made does not use the required protocols, transport Layer Security version 1.2 (TLS 1.2) and Hypertext Transfer Protocol version 1.1 (HTTP/1.1) are mandatory for communication with PayPal. You can test whether or not your server is connecting with the required protocols using cURL from your servers command line, for example:
If successful, this response will be shown:
If unsuccessful, this error will be shown:
ERROR! Connection is using TLS version lesser than 1.2. Please use TLS1.2
The WHMCS PayPal module does not specify a particular cryptographic protocol when communicating with PayPal. This means that cURL on your server should automatically negotiate the best protocol to use. Should you encounter the error above, it means your server is trying to negotiate a secure connection using one of the cryptographic protocols that PayPal no longer support. In that situation it would be necessary to work with your system administrator to ensure TLS 1.2 or greater is the default protocol on the server.
If the cURL test response is successful, it would be necessary to check a succesful connection to PayPal's callback verification service at can be made.
This can again be checked using cURL from your servers command line, for example:
curl -I
Any errors shown can again be referred to your server administrator to review and resolve.