Camera-based credit card scanning for mobile apps

We integrate camera-based credit card scanning into mobile apps. Manual card entry causes errors and abandonment; our solutions cut input time to 1-2 seconds and reduce cart abandonment by 15-20%. For a $50K monthly revenue app, that can save over $10,000 per month. Integration starts from $500, and typical savings exceed $10,000 monthly. Our team has 5+ years of mobile development experience and 30+ successful payment integration projects.

What are the best libraries for card scanning?

Card.io was historically popular but is no longer maintained — on modern iOS versions there are AVCaptureSession crashes. We don't recommend it for new projects. Stripe CardScan (formerly Bouncer) is a neural network solution on TFLite/CoreML, works offline. On iOS, integrate via SPM: https://github.com/stripe/stripe-ios, on Android via Gradle: com.stripe:stripecardscan. Its code is open, allowing adaptation for specific requirements. Native OCR frameworks (VNRecognizeTextRequest, ML Kit Text Recognition v2) require no third-party dependencies, but you need to implement card region detection and result stabilization (confirmation via 3-5 consecutive identical results).

How to ensure recognition accuracy?

Recognition accuracy depends on shooting conditions. In good lighting, Stripe CardScan achieves 97% correct numbers — 20% more accurate than native solutions in low light. In low light or glare, accuracy drops to 85-90%. We recommend implementing Luhn check and frame illumination in low light. For result stabilization, use confirmation via 3 consecutive matches.

Native frameworks vs. ready SDKs

A ready SDK (Stripe CardScan) provides high accuracy out of the box and reduces development time. But if you need full UI customization or work in specific conditions (non-standard cards, poor lighting) — native Vision/ML Kit give you full control. We combine approaches: for MVP we use Stripe CardScan, for production with unique requirements we write our own module on native APIs.

Recognizable card data

Card number is the primary target, accuracy >95%. Expiry date (MM/YY) is recognized confidently. Cardholder name — OCR handles it worse due to font variability and embossing. We recommend: number + expiry scanned automatically, name manually filled as optional. Never recognize or save CVV/CVC — it's on the back, and storing it violates PCI DSS requirements. This is not just a rule, but a mandatory condition for passing security audit.

Implementation on Flutter

The card_scanner package on pub.dev works via Platform Channels to native SDKs. Alternative: google_mlkit_text_recognition with custom parser. For production apps, Stripe CardScan via FFI is preferable: more accurate and reliable in non-standard conditions (poor lighting, non-standard card design). Flutter developers should consider that some stabilization methods require native code — we help with the wrapper.

Permissions and privacy for App Store review

iOS: NSCameraUsageDescription in Info.plist with wording "for scanning card during payment". Android: uses-permission android:name="android.permission.CAMERA" + runtime request via ActivityResultContracts.RequestPermission. Camera frames are processed only in memory — not saved to disk, not sent to server. This is critical for passing App Store and Play Market review. For more details, see Stripe CardScan documentation.

Scope of work (turnkey solution)

1. Requirements analysis and optimal stack selection (Bouncer, Vision/ML Kit, Flutter package).
2. SDK integration with custom UI (camera preview, card frame, animation).
3. Implementation of stabilization logic and false positive filtering.
4. Testing on different devices and in low-light conditions.
5. Integration documentation and support for store publication.

Timelines and collaboration process

Integration of Stripe CardScan with basic UI: 1-2 days. Custom UI + native Vision/ML Kit with own stabilization logic: 2-3 days. Full cycle — from analysis to deployment — takes 3 to 5 days depending on complexity. Cost is calculated individually, starting from $500. We offer turnkey integration in 1-2 days. Write to us for a free project assessment — we'll analyze requirements and offer the best solution.

In-app card scanning with our solution is 3 times faster than manual entry. With a credit card scanning camera, users can capture details in seconds. We provide mobile OCR for cards that is PCI DSS-compliant. Our services cover credit card number recognition, card scanning on iOS and Android, and we are your trusted Card.io alternative. Want to speed up payments and reduce declines? Contact us to discuss details — we'll analyze requirements and propose the best option.

Payments in Mobile Apps: In-App Purchase, StoreKit 2, Google Billing, Stripe, RevenueCat

In every monetization project, we balance App Store and Google Play policies, PCI DSS requirements, and purchase verification logic on the backend. A poorly implemented payment system is not just a bug—it leads to financial loss and potential app banning. Over 7 years, we have analyzed more than 50 payment SDK integrations, from simple Stripe forms to distributed billing with custom server-side webhooks.

In-App Purchase: Two Platforms, Two Different APIs

If your app sells digital content or subscriptions, Apple and Google require you to use their payment systems. This is non-negotiable: violating App Store rule 3.1.1 or Google Play Developer Policy results in app removal. Physical goods and offline services are a different story.

StoreKit 2 (iOS 15+)

StoreKit 2 is a complete overhaul of the original StoreKit with async/await API. Product.products(for:), product.purchase(), Transaction.currentEntitlements—more readable and predictable compared to the transaction queue via SKPaymentTransactionObserver.

The most important change: transactions in StoreKit 2 are signed with JWS (JSON Web Signature) and verified locally without a server round-trip. Transaction.verificationResult returns .verified(Transaction) or .unverified(Transaction, VerificationError). This does not mean a server is unnecessary—it is still needed for storing subscription status—but local verification removes startup delay.

StoreKit.AppTransaction verifies the actual app download from the App Store. Required for paid downloads or non-renewing purchases.

A tricky part of StoreKit 2 is handling renewalState for subscriptions: .subscribed, .expired, .inBillingRetryPeriod, .inGracePeriod, .revoked. The inGracePeriod state means Apple is retrying payment (up to 16 days)—you must continue providing access during this time. Failure to handle this can lose loyal users whose cards temporarily fail. Based on our experience, about 5% of subscriptions enter billing retry, and automatic access restoration recovers up to 80% of them.

Google Play Billing Library (v6+)

Google Billing is more complex than StoreKit in terms of scenario handling. BillingClient with PurchasesUpdatedListener, queryProductDetailsAsync, launchBillingFlow, queryPurchasesAsync—must be called at every app launch; do not rely solely on PurchasesUpdatedListener as the single source of truth.

Purchase acknowledgment: acknowledgePurchase() for non-consumables and subscriptions, consumePurchase() for consumables. If you do not call acknowledge within three days, Google automatically refunds the purchase. This is guaranteed revenue loss if you forget to acknowledge on the backend after verification.

ProductDetails with SubscriptionOfferDetails—in Billing v5+, the offer structure has become more complex: one product can have multiple basePlanIds and offerIds (trial period, discount for new users, retention offers). BillingFlowParams.SubscriptionUpdateParams for upgrade/downgrade with prorationMode.

Why Is Server-Side Verification Mandatory?

Never trust only client-side code when unlocking paid content. Client-side verification can be bypassed by modifying the app.

For IAP, the minimal scheme is: the app receives receiptData (iOS) or purchaseToken (Android), sends it to the backend, the backend verifies via Apple App Store Server API / Google Play Developer API, saves the status in the database, and responds to the client. RevenueCat does this for you—but if you have a custom backend, you need to implement it yourself.

Webhooks are more important than they seem. Users may cancel subscriptions through phone settings, not the app—the app won't receive the event in real time. Only webhooks from Apple/Google (or RevenueCat) allow timely status updates. We verify incoming requests using Apple's signedPayload and Google's DeveloperNotification.

How Does RevenueCat Simplify Integration?

Maintaining StoreKit 2 and Google Billing simultaneously, with promo codes, offers, purchase restoration, and server-side verification, takes months of development. RevenueCat handles most of this layer.

RevenueCat is not just a payment SDK. It offers:

• A unified API for iOS and Android (and Stripe for web)
• Server-side verification and subscription status storage
• Webhooks for events (purchase, renewal, cancellation, billing issue)
• Analytics for cohorts, MRR, churn
• A/B testing of offers via Experiments

Purchases.configure(withAPIKey:) at startup, Purchases.shared.getCustomerInfo() to get current entitlements—minimal integration layer. Purchases.shared.purchase(package:) instead of directly calling StoreKit/Billing.

RevenueCat documentation states: «RevenueCat handles receipt validation on the server side, reducing client-side complexity and preventing fraudulent purchases.»

Limitations of RevenueCat: it is paid (free up to $2.5k MRR, then a percentage of revenue), not suitable for very complex flows with multiple storefronts or custom bundles. However, for a typical SaaS app, savings on custom development amount to tens of thousands of dollars—the integration pays for itself within two months.

Stripe in Mobile Apps

Stripe is used for physical goods, services, and B2B payments where IAP is not required by platform policy.

Stripe iOS SDK and Android SDK—PaymentSheet for ready-made payment UI, PaymentSheetFlowController for custom UI with saved cards. Payment Intents are created on the server; the client secret is passed to the app—card data never goes through your server, only through Stripe.

Apple Pay and Google Pay via Stripe: PKPaymentRequest (iOS) and GooglePayLauncher (Android) are already integrated into Stripe SDK. Apple Pay conversion rates are 1.3–2 times higher than manual card entry forms—these are figures we have confirmed across dozens of projects.

Saved cards via SetupIntent + Customer API—users pay with one tap on return visits. Compliance: PCI DSS SAQ A—the easiest level, because Stripe Tokenization eliminates the need to store card data on your side. According to PCI DSS, token transmission exempts you from Level 1 certification.

3DS2 (Strong Customer Authentication) is mandatory for payments in the EU under PSD2. Stripe handles it automatically via PaymentIntent.confirmPayment, but you need to correctly handle the .requiresAction status and return the user to the appropriate screen after authentication.

What Is Included in the Work (Deliverables)

Process and Timeline

We start by clarifying the business model: subscriptions, one-time purchases, consumables, freemium. The architecture depends on this. Testing IAP requires Sandbox accounts (Apple) and License Testers (Google)—this is a separate environment setup.

Apple's Sandbox behaves differently from production: subscriptions renew every 5 minutes instead of monthly, inGracePeriod works differently. It is essential to test scenarios: trial expiration, cancellation, billing retry, refund.

The cost is calculated individually based on the set of tools and complexity of server-side logic. On average, we fit within a budget for a typical integration, but the savings from preventing errors and churn offset this investment within a few months.

Get a consultation for your project—contact us. We will help you choose the optimal payment architecture that passes store reviews and does not break under peak loads.