Subscription-based businesses need much more than a simple payment gateway. They must manage recurring payments, monthly and annual plans, invoices, free trials, upgrades, downgrades, failed payments, discounts, usage charges, and customer cancellations.
A subscription billing platform brings all these operations into one centralized system.
Chargebee is a well-known subscription and revenue management platform that helps businesses manage recurring billing, subscriptions, invoicing, pricing models, payment integrations, and related revenue operations.
If you are planning to build a SaaS product, membership platform, AI tool, or another subscription-based business, developing a billing platform can help automate the entire customer billing lifecycle.
However, building a platform like Chargebee requires more than charging a customer’s card every month. You need a reliable billing engine, subscription lifecycle management, invoices, payment integrations, webhooks, usage tracking, and accurate financial records.
In this guide, we will explain how to build a subscription billing platform like Chargebee from scratch.
1. What Is a Subscription Billing Platform?
A subscription billing platform is software that helps businesses charge customers repeatedly for products or services.
For example, imagine a SaaS company offering three plans:
Starter Plan – ₹499/month
Professional Plan – ₹1,499/month
Business Plan – ₹4,999/month
When a customer selects the Professional Plan, the billing platform creates a subscription and connects it with the customer’s payment method.
It then manages future billing automatically.
When the next billing date arrives, the platform can generate an invoice, initiate the payment through an integrated payment provider, record the result, and update the customer’s subscription.
A subscription billing platform can manage:
- Monthly and annual subscriptions
- Customers
- Products and pricing plans
- Recurring payments
- Invoices
- Free trials
- Coupons and discounts
- Upgrades and downgrades
- Failed-payment recovery
- Usage-based billing
- Seat-based pricing
- Taxes
- Refunds
- Payment gateways
- Subscription analytics
Therefore, businesses do not need to develop all of this billing logic inside every individual application.
2. How Does a Subscription Billing Platform Work?
The basic subscription workflow is relatively simple.
A customer first chooses a product or subscription plan.
The application sends the subscription request to the billing platform.
The billing platform creates the customer and subscription records, calculates the amount due, generates an invoice, and communicates with the configured payment provider.
A simplified flow looks like this:
Customer → Subscription → Invoice → Payment Provider → Payment Result → Subscription Updated
Suppose a customer subscribes to a ₹1,499 monthly plan.
The system creates something similar to:
Customer: Rahul
Plan: Professional
Price: ₹1,499
Billing Cycle: Monthly
Status: Active
Next Billing Date: 10 OctoberWhen October 10 arrives, the billing engine processes the next renewal.
If payment succeeds, the invoice becomes paid and the next billing period begins.
If payment fails, the subscription can enter a past-due state and the platform can begin its payment-recovery process.
Example: A subscription billing dashboard where businesses can manage customers, subscriptions, invoices, and recurring payments.
This basic workflow becomes more complicated when customers change plans, use coupons, consume metered services, cancel subscriptions, or fail to make payments.
That is why the billing engine is the most important part of the platform.
3. Decide What Type of Billing Platform You Want to Build
Before development begins, define your target market.
Trying to support every possible billing model in version one will make development unnecessarily complicated.
SaaS Billing
This model works well for software companies charging customers monthly or annually.
Examples include:
- CRM software
- Project management tools
- AI applications
- Cloud storage
- Marketing platforms
- Developer tools
Membership Billing
This model can support:
- Gyms
- Coaching businesses
- Online communities
- Educational platforms
- Professional memberships
Usage-Based Billing
Customers pay according to their actual consumption.
For example:
Base subscription: ₹1,000/month
API requests included: 100,000
Additional usage:
₹0.10 per 1,000 requestsUsage billing is particularly relevant for APIs, cloud infrastructure, communication platforms, and AI products.
Seat-Based Billing
Businesses pay according to the number of users using the software.
For example:
₹500 per user/month
20 users × ₹500
= ₹10,000/monthFor your first MVP, fixed monthly and annual SaaS subscriptions are usually much easier to implement.
You can introduce usage and seat-based billing later.
4. Create a Flexible Product Catalog
Your billing platform needs a product catalog where businesses define what they sell.
Avoid storing everything as a single subscription plan.
Instead, separate products and prices.
For example:
Product
└── Project Management Software
Prices
├── Starter Monthly – ₹499/month
├── Starter Annual – ₹4,999/year
├── Pro Monthly – ₹1,499/month
└── Pro Annual – ₹14,999/yearThis architecture allows the same product to have different prices and billing periods.
You can later support:
- Monthly pricing
- Annual pricing
- Per-user pricing
- Usage pricing
- Tiered pricing
- Volume pricing
- One-time charges
- Add-ons
This makes your billing platform flexible enough to support different SaaS business models.
5. Design the Subscription Lifecycle
Subscriptions should always have clearly defined states.
For example:
Trial
↓
Active
↓
Past Due
↓
CancelledYou may also need:
Future
Paused
Non-Renewing
ExpiredEach subscription should contain information such as:
Subscription ID
Customer ID
Product ID
Price ID
Quantity
Status
Start Date
Trial End Date
Current Period Start
Current Period End
Next Billing Date
Cancellation DateThe backend should control valid transitions between subscription states.
For example, if a customer cancels at the end of the billing period, you should not immediately remove their access.
Instead:
Status: Active
Cancel at Period End: Yes
Access Until: 10 OctoberThe subscription can remain active until the paid period expires.
This creates a much better customer experience.
6. Choose the Right Technology Stack
Subscription billing requires reliable backend infrastructure because renewals happen automatically without the customer actively using your application.
A modern technology stack could include:
Next.js – Merchant Dashboard
Use Next.js to build:
- Billing dashboards
- Customer management
- Subscription management
- Product catalogs
- Invoice management
- Reports
- Developer settings
Flutter – Mobile Application
Flutter can be used for Android and iOS merchant applications.
Businesses can monitor subscriptions, payments, failed renewals, and revenue from mobile devices.
Node.js + NestJS – Backend
NestJS works well for a large modular billing backend.
Separate modules can handle:
Authentication
Customers
Products
Prices
Subscriptions
Invoices
Payments
Usage
Discounts
Webhooks
ReportsPostgreSQL – Primary Database
PostgreSQL is a strong choice because subscription billing contains highly relational data.
Customers connect to subscriptions, subscriptions connect to prices, invoices connect to invoice items, and payments connect to invoices.
Redis
Redis can support:
- Caching
- Rate limiting
- Temporary locks
- Distributed coordination
However, Redis should not become the authoritative source for financial records.
Message Queue
A durable queue is useful for background operations such as:
Subscription renewals
Invoice generation
Payment retries
Email delivery
Webhook delivery
Usage processingThis prevents long-running billing operations from blocking normal API requests.
7. Design the Billing Database
Database design is extremely important because billing records must remain accurate over time.
Your database can include the following main entities.
Organizations
Businesses using your billing platform.
Customers
Subscribers belonging to each organization.
Products
Products or services sold by the business.
Prices
Price, currency, billing interval, and pricing model.
Subscriptions
The relationship between customers and purchased products.
Subscription Items
Individual plans, add-ons, quantities, or usage components attached to subscriptions.
Invoices
Financial documents generated for customers.
Invoice Items
Individual charges, discounts, taxes, and adjustments.
Payments
Payment attempts and transaction references.
Refunds
Full or partial refunds associated with payments.
Coupons
Discount configuration and usage rules.
Usage Events
Metered customer activity.
Webhook Events
Events received from and delivered to external applications.
Historical financial information should not change when the current product configuration changes.
For example, if a product costs ₹1,499 today and becomes ₹1,999 next month, an invoice generated today should still show ₹1,499 permanently.
8. Build the Recurring Billing Engine
The recurring billing engine is the heart of your platform.
Suppose 5,000 subscriptions renew today.
Your system needs to identify the subscriptions that are due without accidentally charging customers twice.
A renewal workflow can work like this:
- Find subscriptions whose billing date has arrived.
- Safely claim the renewal operation.
- Calculate subscription charges.
- Add usage charges if applicable.
- Apply eligible discounts.
- Calculate applicable taxes.
- Generate invoice items.
- Create the invoice.
- Attempt payment where appropriate.
- Record the payment result.
- Update the subscription period.
- Send notifications and webhooks.
Every renewal should be idempotent.
Suppose the server creates an invoice but crashes before updating the subscription.
When the worker runs again, it must detect that the invoice for that billing period already exists.
Otherwise, the customer could receive duplicate invoices or charges.
9. Build Invoice Management
Invoices are one of the most important parts of a billing platform.
A typical invoice may look like:
Invoice #INV-10542
Professional Plan ₹1,499
Extra Users × 2 ₹400
Discount -₹200
Tax ₹306
Total ₹2,005
Paid ₹2,005
Balance ₹0Each invoice should contain:
- Invoice number
- Customer details
- Billing address
- Currency
- Invoice date
- Due date
- Subscription reference
- Line items
- Discounts
- Taxes
- Total
- Amount paid
- Amount remaining
- Payment status
Common invoice states include:
Draft
Open
Paid
Partially Paid
Void
UncollectibleGenerate downloadable invoice documents where required.
Most importantly, preserve the historical invoice after it has been finalized.
10. Integrate Payment Gateways
You do not need to build your own payment processor.
Instead, connect your billing platform with existing payment providers.
Your architecture can use a payment abstraction layer:
Subscription Platform
↓
Payment Service
↓
Payment ProviderFor example, your internal interface might support operations such as:
createCustomer()
attachPaymentMethod()
chargeInvoice()
refundPayment()
retrievePayment()Then individual payment-provider integrations implement those operations.
This architecture makes it easier to add additional providers later.
For example, businesses in different countries may prefer different payment gateways.
Additionally, avoid storing raw card details yourself whenever possible.
Use supported tokenization, hosted payment fields, or checkout components provided by your payment partners.
11. Add Free Trials
Free trials are common in SaaS products.
For example:
Professional Plan
14-Day Free Trial
Then ₹1,499/monthWhen the customer starts the trial:
status = trialing
trial_start = September 1
trial_end = September 15When September 15 arrives, the backend determines what happens next.
If the customer has a valid payment method, the system may create the first invoice and attempt payment.
If payment information is missing, your configured business rules determine whether the subscription expires or asks the customer to add a payment method.
Support scenarios such as:
- Trial cancellation
- Trial extension
- Trial conversion
- Payment method added during trial
- Trial without payment information
The backend—not the mobile app or browser—should control trial expiration.
12. Handle Subscription Upgrades and Downgrades
Customers frequently change subscription plans.
Suppose a customer currently uses:
Starter
₹1,000/monthHalfway through the billing cycle, they upgrade to:
Professional
₹2,000/monthYour platform needs clear rules for the change.
Immediate Change With Proration
Upgrade immediately and calculate an adjustment based on the remaining billing period.
Immediate Change Without Proration
Upgrade immediately but do not create a partial-period adjustment.
Change on Next Renewal
Keep the Starter plan until the current billing period ends.
Then activate Professional at the next renewal.
These rules should be configurable because different SaaS companies use different billing strategies.
Your system must also preserve a clear history of plan changes.
13. Add Coupons and Discounts
Businesses often use discounts to attract customers.
For example:
WELCOME20
20% discount
Valid for first 3 monthsAnother promotion might be:
SAVE500
₹500 off
First invoice onlySupport different discount types:
- Percentage discounts
- Fixed discounts
- One-time discounts
- Recurring discounts
- Limited-duration discounts
- Product-specific coupons
- Customer-specific discounts
You should also support:
Start date
Expiration date
Maximum redemptions
Redemptions per customer
Eligible productsThe billing engine should verify eligibility before applying a discount.
14. Build Usage-Based Billing
Usage-based billing is increasingly important for cloud and AI applications.
Imagine an AI SaaS product with this pricing:
AI Pro
₹2,000/month
Includes:
1 million AI tokens
Additional usage:
Charged according to configured rateThe SaaS application sends usage events to your billing platform.
For example:
{
"subscription_id": "sub_123",
"metric": "ai_tokens",
"quantity": 2500
}Your system records the event.
At the end of the billing period, it calculates the customer’s total billable usage.
The billing engine then adds the usage charge to the invoice.
Usage events should contain unique identifiers so retries do not accidentally count the same activity twice.
You may eventually support:
- API calls
- AI tokens
- Storage
- Bandwidth
- Messages
- Processing minutes
- Generated images
- Active users
This makes the platform useful for modern consumption-based SaaS businesses.
15. Add Seat-Based Billing
B2B SaaS applications frequently charge per user.
For example:
Business Plan
₹500/user/monthA company with 20 billable employees pays:
20 × ₹500
= ₹10,000/monthStore quantity independently:
unit_price = ₹500
quantity = 20If the customer adds five users, quantity becomes:
25Your platform can then apply the configured billing and proration rules.
This architecture can also support pricing based on devices, locations, projects, or other measurable quantities.
16. Build Failed-Payment Recovery and Dunning
Recurring payments sometimes fail.
Possible reasons include:
- Expired payment method
- Insufficient balance
- Authentication requirements
- Bank decline
- Temporary payment-provider failure
Do not automatically cancel every subscription after the first failed payment.
Instead, create a configurable recovery process.
For example:
Payment Failed
↓
Retry after 1 day
↓
Retry after 3 days
↓
Retry after 5 days
↓
Final Recovery ActionYou can send notifications between attempts.
For example:
We couldn’t process your subscription payment. Please update your payment method to continue your subscription.
After all retries fail, the merchant can decide whether to:
- Keep the subscription past due
- Pause access
- Cancel the subscription
- Mark the invoice uncollectible
A good dunning system can help businesses recover revenue that would otherwise be lost.
17. Build a Customer Self-Service Portal
Customers should be able to manage common billing operations without contacting support.
A secure customer portal can allow users to:
- View their subscription
- View current plan
- Upgrade
- Downgrade
- Update billing information
- Update payment method
- Download invoices
- View payment history
- Cancel their subscription
The merchant should decide which actions customers are allowed to perform.
For example, some B2B companies may disable direct cancellation because subscriptions are controlled by contracts.
Use secure, short-lived portal sessions rather than exposing sensitive account-management functionality through predictable URLs.
18. Implement Webhooks
The customer’s application needs to know when billing events occur.
Suppose a subscription payment succeeds.
Your billing platform can send:
invoice.paidIf a subscription is cancelled:
subscription.cancelledUseful webhook events include:
customer.created
subscription.created
subscription.updated
subscription.cancelled
invoice.created
invoice.paid
invoice.payment_failed
payment.succeeded
payment.failed
refund.succeededWebhook requests should include signatures so receiving applications can verify that events actually came from your platform.
Your webhook infrastructure should also support:
- Unique event IDs
- Delivery history
- Automatic retries
- Exponential backoff
- Signature verification
- Duplicate-event protection
Never assume a webhook will be delivered exactly once.
19. Build Developer-Friendly APIs
If other SaaS companies will use your billing platform, your APIs become one of your most important products.
Provide clean endpoints such as:
POST /v1/customers
GET /v1/customers/{id}
POST /v1/products
POST /v1/prices
POST /v1/subscriptions
GET /v1/subscriptions/{id}
POST /v1/subscriptions/{id}/cancel
GET /v1/invoices
POST /v1/usage-eventsProvide documentation covering:
- Authentication
- API keys
- Customers
- Products
- Prices
- Subscriptions
- Invoices
- Payments
- Refunds
- Usage events
- Webhooks
- Pagination
- Errors
- Idempotency
Developers should be able to integrate your platform without needing support for every basic operation.
Later, you can provide SDKs for:
JavaScript / TypeScript
Flutter / Dart
Python
PHP
Java
Go20. Provide Test and Live Modes
Developers should never need to test subscription logic using real customer payments.
Create two separate environments.
Test Mode
Developers can create fake customers, subscriptions, invoices, and payment events.
Live Mode
Processes real billing operations through configured payment providers.
Keep credentials separate.
For example:
Test Key
test_xxxxxxxxx
Live Key
live_xxxxxxxxxYour testing environment should allow developers to simulate:
- Successful payment
- Failed payment
- Trial expiration
- Subscription renewal
- Upgrade
- Downgrade
- Cancellation
- Refund
- Webhook failure
You can also create a test clock that allows developers to move simulated time forward.
Instead of waiting one month to test renewal, they could advance the subscription to its next billing date.
This can significantly improve the developer experience.
21. Add Multi-Currency Support
Businesses serving international customers may need multiple currencies.
For example:
Professional Plan
India
₹1,499/month
United States
$29/month
Europe
€27/monthStore each price separately.
Do not automatically convert every transaction using current exchange rates unless dynamic conversion is explicitly part of your business model.
Currency-specific pricing gives merchants more control over regional pricing.
Also ensure that every invoice permanently stores the currency used when it was generated.
22. Add Tax Management
Taxes can become complicated when businesses operate across multiple regions.
Your billing platform can provide a tax configuration layer.
Businesses may configure:
- Tax-inclusive prices
- Tax-exclusive prices
- Customer tax information
- Product tax categories
- Regional tax rules
For complex international requirements, integrating a specialized tax provider may be more practical than maintaining every tax rule yourself.
If your platform serves Indian businesses, its billing architecture may also need to support applicable GST requirements.
Always preserve the tax information used for a finalized invoice.
23. Build Entitlement Management
Billing determines what customers pay.
Entitlements determine what customers can access.
For example:
Starter
Users: 5
Storage: 10 GB
Projects: 10
Advanced Analytics: NoProfessional
Users: 25
Storage: 100 GB
Projects: Unlimited
Advanced Analytics: YesStore these capabilities as structured entitlements.
For example:
max_users = 25
storage_gb = 100
unlimited_projects = true
advanced_analytics = trueWhen a customer upgrades, their entitlements change.
This is much cleaner than placing plan-name checks throughout an application.
Instead of:
if plan == professionalthe SaaS application can check whether a specific feature is enabled.
This also makes future pricing changes easier.
24. Build the Merchant Dashboard
Businesses using your billing platform need a centralized dashboard.
The dashboard should provide a clear overview without becoming overcrowded.
Overview
Display important metrics such as:
Active Subscriptions
Monthly Recurring Revenue
New Customers
Trials
Failed Payments
Recent InvoicesCustomers
Allow merchants to search and manage customer accounts.
Subscriptions
Provide filters for:
Active
Trialing
Past Due
Paused
CancelledProducts
Manage products, prices, add-ons, and billing models.
Invoices
View paid, open, failed, and other relevant invoices.
Developers
Manage:
API Keys
Webhooks
API Logs
Test ModeSettings
Configure payment providers, taxes, currencies, billing rules, and notifications.
Keep detailed reports on separate screens instead of placing every possible metric on the main dashboard.
25. Add Subscription Analytics
Businesses need analytics to understand subscription performance.
Useful metrics include:
- Monthly Recurring Revenue (MRR)
- Annual Recurring Revenue (ARR)
- Active subscriptions
- New subscriptions
- Cancelled subscriptions
- Churn rate
- Trial conversion rate
- Failed payments
- Recovered revenue
- Expansion revenue
Be careful when calculating recurring revenue.
For example, receiving ₹12,000 for an annual subscription does not necessarily mean the business generated ₹12,000 of MRR.
Metric definitions should remain consistent across reports.
Additionally, distinguish actual payment revenue from subscription forecasts.
26. Implement Multi-Tenant Architecture
If your billing platform is a SaaS product, many businesses may use the same system.
For example:
Billing Platform
│
├── Company A
│ ├── Customers
│ ├── Subscriptions
│ └── Invoices
│
└── Company B
├── Customers
├── Subscriptions
└── InvoicesCompany A must never access Company B’s billing information.
Every relevant database record should therefore have clear tenant ownership.
Your backend must validate:
Authenticated User
↓
Organization
↓
Role
↓
Requested Resource
↓
PermissionDo not rely only on frontend restrictions.
Tenant isolation must be enforced by backend and database architecture where appropriate.
27. Implement Security and Audit Logs
Subscription billing platforms contain customer information, financial records, API credentials, and payment references.
Security must therefore be included from the beginning.
Implement:
- HTTPS
- Secure authentication
- Role-based access control
- Tenant isolation
- Secure API key storage
- Secret rotation
- Database backups
- Rate limiting
- Encryption where appropriate
- Secure payment integrations
- Monitoring
- Audit logs
Important actions should create audit records.
For example:
Subscription upgraded
Professional → Business
Changed by: Admin User
Time: 2:30 PMOther important events include:
Invoice voided
Refund created
Discount applied
Subscription cancelled
API key generated
Payment provider changedThis makes financial operations easier to investigate.
28. Test Important Billing Edge Cases
Billing systems need much more testing than ordinary CRUD applications.
Test scenarios such as:
- Renewal worker executes twice
- Customer upgrades before renewal
- Customer downgrades during a trial
- Payment succeeds after an API timeout
- Duplicate payment webhook arrives
- Same usage event arrives twice
- Coupon expires during subscription
- Customer changes seat quantity
- Payment provider becomes unavailable
- Customer cancels while payment is processing
- Refund happens after cancellation
- Annual plan changes to monthly
- Currency configuration changes
- Tax configuration changes
Automated tests are especially important for:
Billing calculations
Proration
Renewals
Invoices
Discounts
Usage aggregation
RefundsEven a small billing bug can affect thousands of customers when recurring jobs execute automatically.
29. How Much Does It Cost to Build a Platform Like Chargebee?
The cost depends on the scope of your billing platform.
A basic subscription management MVP is much smaller than a complete enterprise revenue-management system.
A practical roadmap can be divided into phases.
Phase 1 – Core Billing
Build:
Customers
Products
Prices
Subscriptions
Invoices
Recurring billing
One payment gateway
Basic dashboardPhase 2 – SaaS Billing
Add:
Trials
Coupons
Upgrades
Downgrades
Proration
Customer portal
Webhooks
DunningPhase 3 – Advanced Billing
Introduce:
Usage billing
Seat billing
Multiple currencies
Multiple payment providers
Tax integrations
Entitlements
Advanced analyticsPhase 4 – Enterprise Billing
Add:
Account hierarchies
Custom contracts
Advanced permissions
Revenue workflows
Enterprise integrations
Advanced reportingStarting with a focused MVP helps reduce development cost while allowing you to validate your product with real SaaS businesses.
30. Frequently Asked Questions
Can I build a subscription billing platform using Flutter?
Yes.
Flutter can be used for merchant mobile applications, customer subscription management, payment history, and billing dashboards.
However, recurring billing logic should run securely on your backend.
Can I use Firebase or Supabase?
Yes.
Firebase can support authentication, notifications, and selected application functionality.
Supabase can provide PostgreSQL, authentication, storage, and realtime capabilities.
For billing records, a carefully designed relational database such as PostgreSQL is particularly useful.
Do I need to create my own payment gateway?
No.
You can integrate your subscription platform with existing payment providers.
Your platform can focus on subscriptions, invoices, pricing, usage, analytics, and recurring billing.
Can I build a Chargebee alternative for SaaS companies?
Yes.
Start with a specific customer segment rather than trying to reproduce every enterprise feature immediately.
For example, you could initially build a billing platform specifically for Indian SaaS startups, AI products, or small B2B software companies.
Can the platform support AI usage billing?
Yes.
You can track units such as:
- AI tokens
- API calls
- Generated images
- Processing minutes
- Storage
- Messages
These usage events can then be converted into invoice charges according to configured pricing rules.
How long does it take to build?
A focused MVP may take several months depending on the development team, payment integrations, billing models, and required security.
A mature enterprise billing platform requires significantly more development, testing, integrations, and ongoing maintenance.
Conclusion
Building a subscription billing platform like Chargebee requires much more than automatically charging customers every month.
A reliable platform needs a product catalog, subscription lifecycle, recurring billing engine, invoices, payment integrations, trials, discounts, upgrades, failed-payment recovery, webhooks, and accurate financial records.
Start with fixed monthly and annual subscriptions.
Then introduce features such as proration, dunning, customer portals, usage billing, seat-based pricing, entitlements, multiple currencies, and advanced analytics.
Most importantly, every billing operation should be accurate, traceable, secure, and safe to retry.
With a modular architecture, you can start with a focused SaaS billing product and gradually develop it into a much larger subscription and revenue-management platform.
Want to Build Your Own Subscription Billing Platform Like Chargebee?
Planning to build a recurring billing system, SaaS subscription platform, usage-based billing solution, payment management application, or custom revenue-management software?
At Dotcube Technologies, we help businesses design and develop custom web and mobile applications based on their subscription and SaaS requirements.
Whether you need subscription management, recurring billing, invoicing, payment gateway integration, usage metering, customer portals, webhooks, analytics, or a complete SaaS billing platform, the solution can be planned around your business model.
Want to discuss your subscription billing platform idea?
