How to Set Up Castle for Automated Bitcoin Treasury Management

Most small business owners who want bitcoin on their balance sheet face a frustrating reality: manually buying bitcoin every week takes time, requires constant attention, and introduces emotional decision-making into what should be a straightforward allocation strategy. Castle launched in 2025 specifically to solve this problem, letting businesses automatically convert a percentage of revenue into bitcoin without lifting a finger after initial setup.

The platform raised $1 million in an oversubscribed pre-seed round in June 2025, backed by Boost VC, Winklevoss Capital, and others. That funding reflected growing interest in bringing the corporate bitcoin treasury trend, previously dominated by public companies like MicroStrategy, down to restaurants, e-commerce stores, SaaS companies, and other SMBs.

Here's how to get it running for your business.

Creating Your Castle Account

Start at savewithcastle.com or go directly to dashboard.savewithcastle.com/sign-up. The signup process asks for your name, email, and password. There are no monthly fees, which removes one common friction point for businesses experimenting with bitcoin allocation.

After creating your account, you'll need to complete identity verification. Castle works with regulated U.S. custodians and exchanges, which means standard KYC requirements apply. Have your business documentation ready to speed this along.

Connecting Your Payment Processors

The core of Castle's automation comes from integrating with the tools you already use to collect revenue. The platform supports connections to:

• Stripe for online payments
• Shopify for e-commerce
• Square for in-person transactions
• PayPal for flexible payment acceptance

To connect Stripe, for example, navigate to the integrations section of your Castle dashboard and select Stripe from the available options. You'll authorize Castle to read your transaction data through Stripe's standard OAuth flow. This gives Castle visibility into incoming revenue without requiring you to manually report sales figures.

The same general process applies to other payment processors. Each integration typically takes a few minutes and follows the familiar pattern of authorizing third-party access through the payment provider's own interface.

Linking Bookkeeping Software

If your business runs on QuickBooks or Xero, connecting these platforms gives Castle a more complete picture of your cash position. This matters because Castle can use your actual financial data to make smarter decisions about when and how much bitcoin to purchase.

In the integrations menu, select your accounting software and complete the authorization. Once connected, Castle can reference your cash balances when executing its automated buying strategies.

Configuring Your Buying Strategy

This is where Castle becomes genuinely useful. Rather than setting calendar reminders to buy bitcoin manually, you define rules that Castle follows automatically.

Percentage-Based Allocation

The most straightforward approach: tell Castle to convert a fixed percentage of incoming revenue into bitcoin. Many businesses start with 5-10% as a reasonable allocation that builds bitcoin exposure without straining cash flow.

For example, if your Stripe account processes $50,000 in monthly revenue and you set a 5% allocation, Castle will automatically purchase approximately $2,500 worth of bitcoin over that period.

Cash Balance Thresholds

Castle also supports threshold-based triggers. You can set rules like "buy bitcoin when cash balance exceeds $100,000" or "sell bitcoin if cash drops below $25,000." This approach keeps your bitcoin allocation responsive to actual business conditions rather than following a rigid schedule.

Exposure Limits

To prevent over-allocation, you can set minimum and maximum bitcoin exposure limits. This acts as a guardrail, ensuring your treasury stays within parameters you're comfortable with regardless of what the automated rules might otherwise do.

Understanding Custody and Execution

Castle routes purchases through regulated U.S. exchanges and custodians, focusing on secure, low-fee execution. The platform explicitly avoids leverage and aggressive trading strategies, positioning itself as a tool for long-term bitcoin allocation rather than speculation.

This conservative approach makes sense for businesses treating bitcoin as a treasury asset rather than a trading position. You're not trying to time the market; you're building exposure gradually over time.

What Castle Won't Do

It's worth being clear about limitations. Castle is designed specifically for bitcoin, not other cryptocurrencies. It's also focused on accumulation strategies rather than active trading. If you want to implement complex derivative strategies or hold multiple digital assets, you'll need different tools.

The platform also requires integration with existing payment infrastructure. If your business operates primarily in cash or uses payment systems Castle doesn't support, the automation benefits won't apply.

Getting Started

The practical path forward: create a free account, connect your primary payment processor, link your bookkeeping software if applicable, and configure a conservative initial allocation (5% is reasonable for most businesses testing the waters). Monitor results for a few weeks before adjusting your strategy.

Automating bitcoin purchases removes the friction and emotional overhead that derails many business treasury strategies. Whether bitcoin proves to be a good long-term inflation hedge for your balance sheet depends on factors no one can predict with certainty. But if you've decided to allocate, doing it consistently and automatically is almost certainly better than doing it manually and inconsistently.