Generate Crypto Invoices with OxaPay: A Step-by-Step Guide for Businesses

Cryptocurrency payments are changing how businesses manage transactions—especially across borders. If you want to send structured payment requests and receive crypto easily, you need crypto invoicing. In this guide, we’ll show you how to generate crypto invoices using OxaPay payment gateway.

This guide is written for merchants, developers, and platforms that want full control over billing in crypto—with automation, security, and customization built-in.

What Is a Crypto Invoice?

A crypto invoice is a digital request for payment. It tells the customer how much they owe you, in which currency, and gives them a secure link to pay with crypto. It also includes an expiration time and other details to help track and manage the payment.

Benefits:

• Global reach with no banking delays
• Lower fees and faster confirmation
• Automatic payment status updates
• Transparent and secure
• Built for automation and scaling

OxaPay gives you all the tools to generate crypto invoices securely and efficiently.

Why Use OxaPay for Crypto Invoices?

OxaPay is designed for businesses that need professional invoicing—not simple payment links. With support for more than 20 cryptocurrencies and deep integration options, it lets you:

• Create invoices via dashboard or API
• Customize branding and content
• Accept multiple crypto assets
• Enable smart features like auto-convert and mixed payments
• Get real-time updates with webhooks
• Start without KYC
• Use fast tools like Oxa Light for navigation

💡 Note: The merchant invoice service is part of the Merchant service. It requires integration. If you need a no-code option, OxaPay also offers Payment Links.

Step 1: Create Your OxaPay Account

1. Visit oxapay.com and click Sign Up
2. Enter your email and create a password
3. Confirm your email address

✅ No KYC required. You’ll access your dashboard immediately.

Step 2: Navigate Your Dashboard with Oxa Light

After logging in, you’ll land on your personal dashboard. Here, you can manage invoices, transactions, integrations, and more.

Tip: Use Oxa Light

Oxa Light appears at the bottom center of the screen. It’s a smart internal search bar. Type things like “create invoice,” “generate API key,” or “withdrawal” and jump directly to the page you need—saving time and clicks.

Step 3: Generate Your Merchant API Key

To generate crypto invoices through OxaPay, your first step is to create a Merchant API Key. This key provides secure access to OxaPay’s invoicing system and allows your platform to create and manage invoices programmatically.

How to Generate the Key:

1. Go to Merchant Service section
2. Click Generate Merchant API Key
3. Fill in the following fields:

Basic Fields:

• Name: Your business or project name (3–30 characters)
• Accepted Currencies: Choose which cryptocurrencies you want to accept. You can select specific ones or click “Select All.”

Advanced Options:

• Underpaid Coverage (%): How much of a shortfall you’re willing to accept. For example, set to 5% to allow payment even if the customer sends slightly less.

✅ Note: This feature is always active. This percentage defines how much below the invoice amount is still accepted. If the payment is below this limit, the customer will see the exact remaining amount and can complete it.

• Fee Paid by Payer: If active, customers will pay the network fee. Otherwise, it’s deducted from your amount.
• Auto Convert to USDT: Automatically convert any received crypto to USDT to avoid volatility.
• Auto Withdrawal: Instantly send payments to your own wallet instead of holding them in your OxaPay balance.
• Mixed Payment: Allows customers to complete underpaid invoices using a different coin.

 Example: A customer pays 90% in BTC. If Mixed Payment is enabled, they can pay the rest with ETH or any other coin you accept.

Additional Customization:

• Callback URL: A secure link where OxaPay will send payment updates (useful for automating systems)
• Description: A general note or order summary
• Thanks Message: Shown to the customer after a successful payment
• Return URL: Where the customer is redirected after payment
• Logo URL (Light/Dark Mode): Upload brand logos for invoice pages
• Default Theme Mode: Choose Light or Dark view
• Organization Color: Customize your brand color on the invoice page

4. Click Generate Merchant API Key. Make sure to store it securely.

 Step 4: Create a Crypto Invoice

Now that you’ve generated your Merchant API key, the next step is to use it to create crypto invoices within your website or application. This typically happens when a customer reaches the checkout stage and selects cryptocurrency as their payment method.

What You Need to Do:

1. First, design a section on your website or app that allows customers to choose “Pay with Cryptocurrency” during checkout.
2. When the customer selects this option, your system should gather the order details, including:
   • Amount to be paid (amount)
   • Base currency (e.g., USD)
   • Order ID or reference number (orderId)
   • Invoice expiration time in minutes (lifeTime)
   • Return URL – the page to redirect the customer after payment
   • Customer email (optional)
   • Any additional details such as a description or thank-you message
3. These details must then be sent to OxaPay through a simple programmatic request using the Merchant API key.

Important Note:

Sample code for this request is available in the OxaPay API code examples, covering multiple programming languages such as PHP, Node.js, and Python. Your developer simply needs to integrate the appropriate snippet into your checkout system and dynamically insert the required order details.

4. Once the request is submitted, OxaPay will return a unique payment link for that specific invoice.
5. This payment link should be immediately displayed to the customer on the checkout page, allowing them to proceed to the crypto payment screen.

✅ By completing this step, the entire crypto invoicing process becomes automated and professional for each order. There’s no need for manual handling or technical knowledge from your customer—everything is handled securely and seamlessly in the background.

Step 5: Monitor Payments and Invoice Status

Once you generate crypto invoices and they go live, you’ll need to track them efficiently. OxaPay provides a full Transactions section where you can view the real-time status of every invoice created.

What You Can Do:

• View all invoice statuses in real time: Paid, Pending, Underpaid, or Expired
• Filter transactions by date, coin, status, or customer info
• See order IDs, invoice IDs, payment amounts, and wallet addresses

Webhooks for Automation:

You can set a callback URL when creating an invoice. This allows your system to automatically receive updates from OxaPay whenever a payment is made, partially paid, or expired. It helps you automate order processing and improve customer service.

Tip: Make sure your webhook endpoint is secure and stable. It should handle all expected invoice events correctly.

Step 6: Customize Your Invoice Experience

OxaPay lets you fully tailor the look, feel, and behavior of your invoices to reflect your brand and operational preferences.

Customization Options:

• Logo and Brand Color: Upload separate logos for light and dark modes, and choose a brand color for your payment page.
• Invoice Texts: Add a clear description of the order, a thank-you message, or extra instructions to guide customers.
• Return URLs: After payment, redirect users to your custom confirmation page.
• Auto Conversion to USDT: If activated, payments are instantly converted to stablecoin to avoid volatility.
• Auto Withdrawal: Automatically transfer funds to your external wallet instead of storing them in your OxaPay balance.

Note: You configure most of these options at the time of generating your API key, but you can also override some settings in individual invoice requests.

Step 7: Recovering Underpaid or Expired Invoices

Sometimes customers don’t complete the full payment before the invoice expires, or they pay less than the required amount. As a merchant, here’s how you can manage those cases:

• If the invoice is underpaid, the customer will see the remaining amount on the payment page and can complete the payment using the same or another accepted coin (if Mixed Payment is enabled). No action is needed from you unless you want to follow up.
• If the invoice is expired but still underpaid, you can reopen the same invoice from your dashboard. This allows the customer to complete the payment using the original link—no need to create a new invoice.

✅ This helps you recover missed payments without disrupting the transaction or requiring the customer to start over.

Putting It All Together: Your Crypto Invoice Flow

Now that you’ve learned each step, here’s how everything connects in a real-world business flow. This summary helps you understand how to generate crypto invoices effectively—what needs to be done once, what happens automatically, and how to integrate the entire process into your site or app with minimal friction.

One-Time Setup:

These are the things you only need to do once:

• Create your OxaPay account – No KYC required.
• Generate your Merchant API Key – Configure accepted coins, fee settings, branding, and smart invoice behavior like underpaid coverage or mixed payment.
• Set up the invoice request code – Your developer should place the code (available in OxaPay docs) in your website or application backend. This will handle invoice creation automatically when needed.

What Happens for Every Order:

This process runs automatically whenever a customer wants to pay with crypto:

1. The customer selects “Pay with Cryptocurrency” during checkout.
2. Your system gathers order info (amount, currency, order ID, return URL).
3. Your system sends this info to OxaPay using your Merchant API Key.
4. OxaPay instantly creates a crypto invoice and returns a unique payment link.
5. Your website shows this link to the customer on the checkout page.
6. The customer completes payment using their preferred coin.
7. OxaPay notifies your system when the invoice is paid, underpaid, or expired.

Bonus: Smart Invoice Handling

• If the payment is underpaid, OxaPay shows the remaining amount automatically.
• If the invoice expires, you can reopen it so the customer can finish payment.

• With Mixed Payment enabled, they can even pay the remainder with another coin.

✅ With this flow in place, you can generate crypto invoices seamlessly and securely—without manually handling invoices, conversions, or confirmations. Everything from creation to completion happens in seconds, giving you full control and scalability.

Final Thoughts: Smarter Invoicing Starts Here

OxaPay crypto payment gateway gives you the flexibility and control you need to build a crypto billing system that works at scale. From professional branding to smart features like underpaid recovery and mixed payments, it’s built for modern businesses.

✅ Whether you’re a developer or a business owner, now is the time to simplify how you generate crypto invoices.

Get started at OxaPay.com and take your invoicing to the next level.

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