How to Build a Crypto Wallet App: Cost and Security

Short answer

Building a crypto wallet app typically costs 80,000 to 250,000 dollars or more, and security dominates the entire project because a wallet holds real value and mistakes are irreversible. The biggest decision is custodial versus non-custodial, which changes the security model, the cost, and the regulatory burden. Private-key handling, blockchain integration, and device security are the core work, and Apple applies specific rules to crypto apps. For the wider financial-app picture, see our guide on the cost to build a fintech app; here we focus on wallets.

Why security is the whole game

With most apps, a security flaw is serious but recoverable: you patch it, reset passwords, and move on. A crypto wallet is different in a way that shapes everything about how it must be built, because the funds it controls are real, and transactions are irreversible. If someone gains access to a user’s keys, the money is gone, permanently, with no bank to reverse it and no support line to call. That single fact makes security not one concern among many but the concern the whole project is organised around.

This is why a crypto wallet costs more than a normal app of similar visible complexity. The interface, sending, receiving, showing a balance, is straightforward. The hard part is everything protecting the keys behind it: how they are generated, where they are stored, how they are used to sign transactions, and how every one of those steps is defended against attack. A wallet that looks finished but has a subtle flaw in key handling is not a working product; it is a disaster waiting to happen. So the budget, the time, and the expertise go overwhelmingly into getting the security right, which is exactly what founders who price the send screen underestimate.

Custodial or non-custodial: the fundamental choice

The first and most important decision in building a wallet is who holds the keys, because it changes almost everything downstream.

Aspect	Custodial	Non-custodial
Who holds the keys	You, the app	The user, on their device
User experience	Simpler, familiar, recoverable	More responsibility on the user
Your responsibility	You hold users’ funds	You never touch users’ funds
Regulatory burden	Heavy, you are holding assets	Lighter, but not zero
Security focus	Protecting your central store	Flawless on-device key handling

In a custodial wallet, you hold the keys and therefore the users’ funds, which is simpler and more forgiving for users but makes you responsible for safeguarding real assets and brings heavy regulation, closer to being a financial institution. In a non-custodial wallet, users hold their own keys and you never have access to their funds, which reduces your regulatory burden and liability but demands that the on-device key handling be flawless, because there is no central safety net. Neither is simply better; they are different products with different costs and obligations, and choosing between them is the decision that shapes the rest of the build.

What it actually takes to build

Beyond the custody decision, a crypto wallet is built from a few demanding pieces, and knowing them clarifies where the cost goes.

• Key management. Generating, storing, and using private keys securely, ideally using the device’s secure hardware and biometrics like Face ID so keys never sit exposed. This is the heart of the app.
• Blockchain integration. Connecting to one or more blockchains to read balances and broadcast transactions, which means integrating with blockchain infrastructure reliably and correctly.
• Transaction handling. Building, signing, and sending transactions accurately, because an error here can send funds to the wrong place irreversibly.
• Device and app security. Protecting the app itself, built natively in Swift to use the iPhone’s security features, against the many ways attackers try to reach keys or funds.

The theme across all of these is unforgiving correctness. In most apps, a small bug is a nuisance; in a wallet, a small bug can be a loss of funds. This is why crypto wallets need genuine security expertise and thorough testing, and why the sensible approach leans on proven, audited cryptographic libraries for the most dangerous parts rather than writing them from scratch. Following Apple’s Human Interface Guidelines keeps the experience clear, which matters because confusing crypto interfaces themselves cause costly user mistakes.

Apple’s rules for crypto apps

Anyone building a crypto wallet has to plan around Apple’s specific rules, because getting them wrong means rejection late in the process. Crypto wallet apps are allowed on the App Store, but Apple’s App Store Review Guidelines set conditions. The scrutiny reflects how much financial crime Apple fights platform-wide: its May 2026 fraud report says the company stopped over 2.2 billion dollars in potentially fraudulent transactions and blocked 5.4 million stolen credit cards from being used in 2025 alone, so a finance app that looks even slightly careless has no chance in review.

Wallets may store and manage cryptocurrency, which is the good news. But there are limits: on-device crypto mining is not permitted, apps facilitating transactions like exchanges generally must come from properly established, often licensed, businesses rather than an individual, and how any in-app purchases relate to crypto is constrained. Apple reviews crypto apps carefully, precisely because real money and security are involved, so the app must be genuinely well built and compliant. The practical lesson is to understand these rules before you design, not after, and to build to a high standard, because a crypto app that looks like it cuts corners on security or skirts the rules is likely to be rejected. Launching still requires an Apple Developer Program account, and the review for a wallet is stricter than for an ordinary app.

The cost and how to scope it

Your situation	Sensible starting scope	Why
Testing the concept	Non-custodial, one blockchain, core send and receive	Lowest regulatory and security surface
Custodial ambitions	Budget for compliance and a hardened central store	Holding funds is heavily regulated
Multi-chain vision	Start with one chain, design to extend	Each chain adds integration and testing
Exchange or staking features	Add after the wallet is proven and compliant	These raise complexity and regulation

The way to control cost without cutting the parts that matter is to narrow the scope, not the security. A sensible first version is a non-custodial wallet for a single blockchain, doing the core actions, generate a wallet, receive, send, and view balance, with security done properly. That proves the product and the hardest engineering while keeping the regulatory and integration surface small. Adding more chains, exchange features, or custodial options are deliberate later steps, each of which raises cost and, often, regulatory burden. What you never trim is the key management and security, because that is the one part of a wallet that cannot be cheap and still be safe.

Recovery and backup: the problem with no bank behind it

One part of wallet design deserves special attention, because it is where good intentions and hard reality collide: recovery. In a normal app, if a user forgets a password, you reset it. In a non-custodial wallet, there is no reset, because you do not hold the keys. If a user loses access to their keys and their backup, their funds are gone, and there is nothing you can do. This changes how you have to design the whole experience.

The standard answer is a recovery phrase, a set of words that can regenerate the wallet, which the user must record and keep safe themselves. Designing this well is a real challenge that is as much about human behaviour as cryptography: you have to make users understand, at the moment they create a wallet, that this phrase is the only way back and that no one, including you, can recover it for them if they lose it. Get this wrong, bury it, rush it, make it confusing, and users lose funds and blame the app, even though the loss was structural. A serious wallet invests genuine design effort here, because the recovery flow is where non-custodial security meets ordinary people, and it is one of the most important and underestimated parts of the build. Custodial wallets trade this problem for the heavier burden of holding funds and recovering accounts themselves, which is the other side of the custody decision made earlier.

When you should not build your own wallet

Be honest about whether building a wallet from scratch is the right move. If your real need is to add simple crypto payments or balances to an existing app, integrating a proven wallet or payment provider is usually far safer and cheaper than building custody yourself, because you avoid taking on the hardest, most dangerous security work. And if you cannot fund genuine security expertise and thorough testing, you should not be holding anyone’s keys or funds, because a half-secured wallet is worse than no wallet at all.

When building a real wallet is the right call, what you are really commissioning is security engineering with an app around it, where the invisible key handling matters far more than the visible screens. A team that designs and builds under one roof, as we do, builds the wallet natively around secure key management and the device’s security hardware, uses audited components for the cryptography, and plans around Apple’s crypto rules from day one. See examples in our work and talk through your wallet or Web3 idea, and its real security requirements, at a short call.