Effortless Usage-Based Billing for Your SaaS
Small Transfers is a payment platform that lets you bill as little as 0.000001 USD per request. You provide the service, we charge your customers, you get paid. Easy.
User-Friendly
Easy Setup
Low-Cost
Trustworthy
Problem & Solution
Decreasing the barrier to entry
Problem
28% feel overwhelmed by subscriptions. Of those that do subscribe, 39% will cancel within the first month. Prepaid bundles have a similar barrier to entry.
Solution
Add pay-as-you-go pricing. Occasional users pay only for what they use. Regular users still choose a subscription because it saves them money. No free trials or bundles.
Example
A simple use case
Your Service
You offer an online service that allows customers to increase the resolution of an image using AI.
Charging
Each time a customer uses your service, you charge their Small Transfers account 0.01 USD. You can authorize maximum cost+margin, then capture actual cost+margin.
Getting Paid
Each month, customers pay their outstanding balances, and we transfer the amounts to your Stripe account.
User-Friendly
Carefully designed APIs
Our API is intuitive and easy to use. Here is an example of how you can authorize a charge:
const url = "https://smalltransfers.com/api/v1/charges";
const response = await fetch(url, {
method: "POST",
headers: {
Accept: "application/json",
"Content-Type": "application/json",
},
body: JSON.stringify({
publishableKey: "<publishable_key>",
secretKey: "<secret_key>",
accessToken: "<access_token>",
currency: "usd",
amountMicros: 10_000, // 0.01 USD
}),
});
See our API Reference and our Next.js Starter Project for details.
Features
Convenience at your fingertips
Easy to Integrate
No products, prices, or subscriptions. Just a simple API.
Spending Limits
We gradually increase how much a customer can owe, which reduces your risk.
Automated Payments
We take care of charging customers, tracking payment methods, retries, reminders, and more.
Authentication Included
The platform authenticates customers, so you don't need to handle authentication yourself.
Data Security
All traffic uses TLS. Data at rest is AES-256 encrypted. We don't store full card details (PCI DSS SAQ A).
Customers
How it works for your customers
Sign-Up Checks
Before using any service, customers must specify their monthly spending limit and add a payment method that passes Stripe Radar and 3-D Secure.
Amount Owed Limit
Each customer also has a limit to the amount they can owe, which starts at 10 USD and increases up to 30 USD with successful payments. The customer is charged as soon as they reach that limit.
Handling Low Usage
If a customer owes less than 1 USD at month end, we delay charging them for up to 60 days. If the amount is still under 1 USD after 60 days, we charge at least 0.50 USD and credit the difference (after fees) to their account for future use.
See the customer page for more details.
Easy Setup
Three simple steps
Connect Stripe
Connect your existing Stripe account or create a new one, so we can easily transfer customer payments to you.
Get Authorization
Send your customers to a page where they can allow you to charge their Small Transfers account. This also serves as customer authentication (OAuth) for your service.
Charge
For each customer request, charge their Small Transfers account by calling a simple API. Customers later pay these charges in batches by card via Stripe — no crypto or tokens.
See our Integration Guide and our Next.js Starter Project for details.
Pricing
Only 3%
You pay a flat 3% fee on the total amount you charge your customers, regardless of the number of charges.
There are no fixed or monthly fees. Payment-processing fees are added to the customer's bill, never to yours.
About us
Who built this?
Small Transfers was founded by Dr Rok Strniša, an entrepreneur with over 15 years of experience in the tech industry.
Rok has obtained his PhD in Computer Science from the University of Cambridge.
He was a networking research engineer at Citrix, a financial engineer at the London hedge fund Winton, and a principal engineer at the tech unicorn Improbable.
Dr Rok Strniša
Founder
Advisors
On the shoulders of giants
We are proud to have the following incredible people as our advisors.
Richard Stein
Payments Advisor
Dr Jat Singh
Policy Advisor
Dr Jean Martina
Security Advisor
FAQ
We're here to answer any questions you may have
Can I set my own price?
Yes, you can charge a different amount for each request, which is useful when your cost varies with each request.
How much can I charge per request?
From 0.000001 USD to 1 USD. If you are thinking of charging a different amount, please get in touch.
What if the customer reaches their spending limit?
The API call will fail. In such cases, you can inform the customer, and they can take an appropriate action.
Do you hold customer funds?
No. After a customer pays, the funds are immediately forwarded to your Stripe account using a Stripe transfer.
Do you perform any checks on customers?
Each customer must provide a payment method that passes our risk checks and is verified with 3D Secure.
What if a customer's payment attempt fails?
We automatically retry their payment method(s), notify them, and pause new charges to their account.
What if a customer never pays?
We transfer only the funds we collect. If a payment is later reversed, we offset that reversal against your future transfers.
How much can each customer owe?
A customer can owe at most 10 USD when they create their account. This can go up to 30 USD with successful payments.
Why use this over Stripe's usage-based billing?
Small Transfers is much easier to integrate with, and includes per-customer spending limits and customer OAuth.
Is the platform blockchain-based?
No. Small Transfers uses its own system for tracking usage, which is settled through Stripe. No crypto, tokens, or wallets.
Can you point me to an existing integration?
Unattach (also created by us) uses Small Transfers to offer a Pay-as-You-Go pricing model to its users.
How can I get in touch?
If you have any other questions, please contact us.
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