Coinepay | How to Pay for Whisper API with a Virtual Card (Step-by-Step)

WhisperAPI (whisper-api.com) is a speech-to-text service that turns audio into transcripts through a developer API. This guide explains how to pay for it using a Coinepay virtual card, from creating your account to clearing checkout. Note that this is the independent WhisperAPI service at whisper-api.com, not OpenAI's own Whisper model API \u2014 the billing described here applies to whisper-api.com.

What you need before you start

Buying WhisperAPI credits is quick once a few things are in place:

A verified Coinepay account. You must register and complete identity verification (KYC) before your virtual card is active. If you haven't yet, create your Coinepay account and finish verification first.
A Coinepay virtual card with funds on it. Open the Coinepay app (iOS or Google Play) or the dashboard to view your card number, expiry date and CVV, and make sure there is enough balance to cover the bundle you want.
Your real billing details. Use the name, address and country that match your Coinepay account and identity. Accurate billing information is what helps the payment pass verification.
A WhisperAPI account. You'll set this up in the next section.

WhisperAPI lists Paddle as its payment processor, and Paddle's checkout accepts credit and debit cards on networks including Visa, Mastercard, American Express, Maestro, UnionPay, JCB, Diners Club and Discover. Whether any individual card is approved still depends on the checkout and the issuing bank. If you're unsure your card meets a requirement, contact Coinepay support to confirm before you buy.

Step 1: Create your WhisperAPI account

Go to whisper-api.com and sign up. The sign-in page offers Google, GitHub and email/password options, so pick whichever you prefer. After registration you land in a dashboard where you can generate an API key. WhisperAPI also provides 5 free credits without a card, which is a good way to test transcription quality before you pay for anything.

Step 2: Choose a credit bundle

WhisperAPI's paid offer is pay-as-you-go credit purchases, not a monthly subscription. On the pricing page you'll see several bundles, each with its own Purchase Credits button. At the time of writing (October 2026), the published US-dollar prices were:

Bundle	Price	Per credit
40 API Credits	$10	$0.25
100 API Credits	$20	$0.20
200 API Credits	$30	$0.15
Custom (min. 1,000 credits)	from $100	$0.10

These prices were shown in US dollars; local totals, taxes and conversion rates in other currencies may differ. Always check the official WhisperAPI pricing page for the current figures before you buy, since plans and prices can change. The site also mentions tailored or enterprise pricing by contacting its support, with no published price.

How far credits go depends on the model size, audio length (billed per started hour), whether you use speaker diarization, and file size. WhisperAPI states that purchased credits do not expire, which suits occasional or bursty workloads.

Step 3: Pay with your Coinepay virtual card

After you select a bundle and click its Purchase Credits button, a Paddle checkout window opens. To complete payment:

Choose card as the payment method if other options are shown. Paddle may also display methods such as PayPal, Apple Pay or Google Pay depending on your location and device; which of these WhisperAPI enables can vary.
Open your Coinepay app or dashboard and copy the card number, expiry date and CVV.
Enter the card details, plus your billing name and address exactly as they appear on your Coinepay account.
Confirm the displayed total and currency, then submit. If your bank triggers 3-D Secure, approve the prompt in the way your issuer requires.

Once the payment clears, your credits are added to your WhisperAPI account and you can start transcribing with your API key. Because these purchases are described as one-time and non-recurring, there is no renewal to cancel afterwards for the listed credit bundles.

Troubleshooting: why a card gets declined

Paddle identifies several common reasons a checkout card payment is declined. Here's how to work through them.

Insufficient funds

If your card balance is lower than the bundle price plus any applicable tax or currency conversion, the charge fails. Check your available balance in the Coinepay app and top up, then try again. Remember the checkout total may be converted into your card's currency.

Billing address mismatch

A nonspecific bank decline can occur when the billing name or address you enter doesn't match your card records. Re-enter the details so they match your Coinepay account exactly, including country. Don't use a made-up address \u2014 use your real billing information.

Invalid CVV or card details

Paddle flags invalid CVV among its decline reasons. Re-copy the CVV, expiry and card number straight from your Coinepay app to rule out a typo, and make sure the card is active.

3-D Secure not completed

If an authentication step appears and isn't finished, the payment won't go through. Complete any verification prompt from your issuer. You can manage authentication and view card activity in the Coinepay app.

Suspected fraud or a nonspecific bank decline

Issuers sometimes block a first-time or cross-border charge as a precaution. Wait a few minutes and retry, or use a different Coinepay card if you have one. If it keeps failing, reach out to Coinepay support to check whether anything on the card side is blocking the transaction.

Region checks

Paddle blocks purchases from the countries and regions it does not support, which include Russia, Belarus, Iran, Cuba, North Korea and specified regions of Ukraine. If you're buying from a supported location, make sure your billing country is entered correctly. Some Coinepay services are also unavailable in certain jurisdictions, so confirm the service is available where you are.

A note on refunds

WhisperAPI's official statements on refunds conflict: its pricing FAQ invites dissatisfied customers to contact support for a full refund, while its terms describe processed payments as non-refundable. Which applies to a specific purchase isn't clear from the public pages, so if a refund matters to you, confirm the current policy with WhisperAPI's support before buying, and keep your purchase confirmation.

Managing your card after purchase

Your Coinepay dashboard and app are available 24/7, so you can check the transaction, review your balance and manage your virtual cards at any time. If you run several services, issuing a separate virtual card for each one with its own spending limit makes it easier to track what you spend on transcription versus other tools. Card issuance and fund services are provided by Coinepay's licensed partner financial institutions.

If you hit a problem that looks card-related rather than merchant-related, contact Coinepay support or reach the team via Telegram. For anything to do with your credits, API key or WhisperAPI billing policy, contact WhisperAPI directly.

Get your Coinepay virtual card: Sign up · App Store · Google Play · Customer support

FAQ

Is WhisperAPI a subscription or a one-time purchase?

WhisperAPI's paid offer is pay-as-you-go credit purchases, described by the service as one-time and non-recurring. The listed credit bundles have no renewal to cancel. Its FAQ mentions a "Pro subscription," but whether that is currently sold is unconfirmed.

Which cards can I use at WhisperAPI checkout?

WhisperAPI uses Paddle, whose checkout accepts credit and debit cards on networks including Visa, Mastercard, American Express, Maestro, UnionPay, JCB, Diners Club and Discover. Approval of any individual card still depends on the checkout and your issuing bank. Contact Coinepay support if you want to confirm your card meets a requirement before buying.

How much do WhisperAPI credits cost?

At the time of writing (October 2026) the published US-dollar prices were 40 credits for $10, 100 credits for $20, 200 credits for $30, and custom bundles from $100 (minimum 1,000 credits) at $0.10 each. Prices can change and may differ in other currencies, so check WhisperAPI's official pricing page.

Why was my Coinepay card declined?

Common Paddle decline reasons include insufficient funds, invalid CVV, suspected fraud and nonspecific bank declines. Check your Coinepay balance, re-enter billing details that match your account, complete any 3-D Secure prompt, and retry. If it persists, contact Coinepay support.

Do I need to verify my identity before paying?

Yes. You must register with Coinepay and complete identity verification (KYC) before your virtual card is active. Use your real name and billing details at checkout so the payment can pass verification.

How to Pay for Whisper API with a Virtual Card (Step-by-Step)