Paddle for WordPress Invoices

Paddle is a merchant of record. It sells to your client on your behalf, which means Paddle registers for, files and remits the sales tax and VAT on that sale instead of you. PaySlate Pro connects Paddle to your WordPress invoices, so the tax question is answered before it becomes a problem. Here is the complete setup: credentials, webhook, tax category, and what your client sees.

Step 1: Get your Paddle credentials

In the Paddle dashboard, create an API key and a client token. Paddle gives you a separate sandbox environment with its own pair, so start there. You will also need the webhook signing secret from the notifications section, which PaySlate uses to prove that an incoming event genuinely came from Paddle.

Step 2: Connect Paddle in PaySlate

In your site’s PaySlate settings, choose Paddle and fill in five fields: Mode (Sandbox or Production), API key, Client token, Webhook signing secret, and Tax category. The keys and the signing secret are stored encrypted. The tax category is the one field people skip, and it matters: it tells Paddle what kind of product you are selling so it applies the right tax treatment.

PaySlate runs one gateway at a time. Every invoice you have already sent keeps the gateway it was created with, so switching to Paddle never breaks an invoice a client is about to pay.

Step 3: Add the webhook

In Paddle, create a notification destination pointing at the URL shown in your PaySlate settings, subscribed to transaction.completed, transaction.payment_failed, transaction.past_due, adjustment.created and adjustment.updated. The first flips your invoice to paid the moment the money clears. The last two keep refunds in sync, so a refund issued in Paddle is reflected on the invoice in WordPress without you touching anything.

PaySlate verifies every event with an HMAC signature and rejects anything with a timestamp more than five minutes old, so a captured request cannot be replayed against your site later.

Step 4: Run a test transaction

With Mode set to Sandbox, send yourself an invoice and pay it with one of Paddle’s test cards. Watch the invoice flip to paid and the receipt arrive. Then switch Mode to Production and swap in your live API key, client token and signing secret.

What your client sees

An invoice on your domain with a pay button that opens Paddle’s hosted checkout. Cards and the wallets your Paddle account has enabled, with tax calculated and shown before they confirm. Your client never creates an account and never lands on a third party’s invoice portal.

Who Paddle is right for

Choose Paddle when you sell across borders and do not want to track tax registration thresholds in every market you happen to sell into. Paddle takes on that filing obligation as the seller of record, and its fee is higher than a plain card processor’s because that work is included in it. If you sell only in your own country and already handle your own tax, Stripe or Square in the free plugin will cost you less per transaction.

Paddle is not tax advice, and your own registration obligations are still yours to understand. What changes is who collects and remits on the sale itself. Lemon Squeezy is the other merchant of record PaySlate Pro supports, and Pro pricing is here.