Do Expense Apps Really Need Your Login and Password? We Didn't Think So.
You've just got back from a group trip. Someone paid for the accommodation, someone covered the supermarket run, a few people put rounds behind the bar. Now you need to work out who owes who — and every expense app you try wants a login before you can do a thing.
Username. Password. Verify your email. Accept the terms. Allow notifications. It's a lot of hassle just to divide up a weekend.
So we asked a simple question when we built Tallykins: do group expense apps actually need a login? We went looking for the honest answer — and it turned out to be more interesting than we expected.
Why most apps default to logins
When developers build an app that stores data, the instinctive move is to create an account system. It's the path of least architectural resistance — tie a user record to the data, and you're done. The problem is that this default gets applied universally, whether it's warranted or not.
A banking app needs to know who you are. A medical records app needs to know who you are. An app that helps eight friends split the cost of a long weekend? The case is much weaker than most developers stop to consider.
An app with no ads, no email marketing, and no interest in your spending behaviour has far less reason to demand your credentials. The login wall is often a business model decision, not a technical one.
What a login actually gives an expense app
It's worth separating the genuine technical need from the assumed one. Here's what requiring a login actually enables for a group expense app — and what it doesn't:
| Action | Needs a login? | Why |
|---|---|---|
| Joining a shared event as a participant | No | A code identifies the event. A screen name identifies the person within it. That's enough. |
| Adding expenses to a shared event | No | The organiser's account handles the cloud sync — participants don't need their own. |
| Viewing balances | No | Read access to shared data doesn't require individual identity verification. |
| Tracking an event on your own phone | No | Data stored on your device doesn't need cloud identity at all. |
| Creating and managing a shared event | Yes | Someone needs to own the event in the cloud. An account anchors that responsibility. |
| Real-time sync across devices | Yes | Cloud sync needs a signed-in owner to know whose data is whose. |
The pattern is clear. If you're organising an event — creating it, managing it, syncing it across devices — some form of account is a genuine technical requirement. But if you're one of the friends joining, adding expenses, and checking balances, you don't need one. At all.
The difference between a new login and an account you already have
This distinction matters more than most people realise. There's a meaningful difference between:
- Creating a new login — choosing a username, inventing a password, verifying an email. You're handing credentials to yet another service that could lose them, misuse them, or one day cease to exist.
- Using an account you already have — Sign in with Google or Sign in with Apple. No new password is created. Your credentials stay with Google or Apple. The app receives a secure token. One important distinction: Sign in with Apple lets you hide your email address entirely using a private relay address. Sign in with Google shares your Google email address with Tallykins — though no password is ever involved.
OAuth — the technology behind Sign in with Google and Sign in with Apple — was designed specifically so that apps don't need to handle passwords. Your credentials never touch the app's systems. Apple goes further still: Sign in with Apple can generate a private relay email address, so you can authorise an app without revealing your real email address at all.
"The most private system isn't one with the best encryption. It's one that holds the least data to begin with."
How we approached it when building Tallykins
When we built Tallykins, we started from a straightforward conviction: you shouldn't have to trade your data just to split costs with friends. That's not a marketing position — it's a design principle that shaped every architectural decision we made.
We asked what the minimum viable data collection actually was. The answer looked like this:
- Participants joining a shared event A 6-character invite code identifies the event. A screen name identifies the person within it. No email, no password to join a shared event — because none of those things are technically necessary.
- Events you don't share or back up Your event data stays on your phone unless you sign in or share. No credentials required, because there's nothing to sync. We do collect anonymous usage and crash data; our Privacy Policy has the details.
- Organisers creating a shared event A genuine technical requirement — someone needs to own the event in the cloud. But owning something in the cloud doesn't require creating a new password. It requires a verifiable identity, which Google and Apple already provide. One tap, no new credentials. If you sign in with Google, your Google email address is shared with Tallykins. Apple users can opt to hide their email entirely.
Building this way was harder than taking the default route. A traditional account system is well-understood territory with established libraries and frameworks. Designing without that scaffolding meant solving problems from scratch — how to sync shared event data across participants with no email or password for any of them, how to make a code-based join feel trustworthy, how to architect local-first storage with an optional cloud layer on top.
We made those choices because we believed the outcome was worth the effort. Not because it was easier.
If you want the full technical picture of what Tallykins collects and stores, our Privacy Policy sets it out plainly.
🐾 Choosing between apps? Login and password requirements are just one factor — see our full guide to choosing a group expense tracker for the complete checklist.
No ads. No sign-in wall. Both for the same reason.
Tallykins has no advertising. That's not a separate decision from the login one — it's the same decision expressed twice.
Ad-supported apps need to identify users to serve targeted ads. Remove that business model, and the case for mandatory accounts largely disappears. The two things are connected: there's no sign-in wall because there's no ad engine behind it, and there's no ad engine because we don't want to build a product that treats users as inventory.
Privacy isn't a feature we added, it's structural: we hold as little as we can, and our Privacy Policy sets out exactly what that is.
What this means in practice
If you're joining a Tallykins event as a participant, you will never be asked for an email address or a password. A 6-character code from the organiser and a screen name of your choosing. That's the entirety of what's required.
If you're the organiser, you sign in with your existing Google or Apple account — one tap, no new password, your credentials never touching Tallykins systems. Apple users can hide their email address entirely.
Unless you sign in or share, your events live on your device. Not on a server. Not somewhere that can be breached or sold.
🐾 Heading somewhere with patchy signal? Not having to sign in is only half the story — see our guide to whether a group expense app actually works offline before you rely on it for a trip.
That's the whole model. Collect as little as we can. Ask for nothing you don't genuinely need. Build the privacy in, rather than promising it afterwards.
No password. No ads. Nothing complicated.
Fair splits with friends — built to respect your privacy from the ground up.
Frequently asked questions
Do I need a login to use a group expense tracker?
It depends on your role. With Tallykins, there's no signup required to join a shared event — just a 6-character join code and a screen name. The organiser who shares the event signs in with an existing Google or Apple account. No new username or password is ever created with Tallykins.
Is there a group expense app with no login required?
With Tallykins, there's no email, no password to join a shared event. You join with a 6-character code and pick a screen name. That's it. The organiser uses Sign in with Google or Sign in with Apple — no new password required.
Why do most expense apps require a login?
Mostly because it's the default in app development, not because it's technically necessary. Apps that carry advertising need to identify users to serve targeted ads. Apps with email marketing need your address to reach you. Neither of those is a reason that benefits you — they benefit the app. An app with no ads and no interest in re-engagement has far less reason to ask for your credentials.
What is the difference between a login and OAuth?
A traditional login means creating a new username and password with the app itself. OAuth — such as Sign in with Google or Sign in with Apple — lets you authorise an app using an account you already have. Your credentials stay with Google or Apple; the app never sees your password. It's more secure and requires nothing new from you.
Can I track shared expenses without giving my email address?
With Tallykins, participants never provide an email address. Organisers who use Sign in with Apple can hide their email entirely using Apple's private relay. Organisers who use Sign in with Google will have their Google email address shared with Tallykins — no new password is created, but the email is received. See our Privacy Policy for full details.
Is a no-login expense app less secure?
Not at all. Emails and passwords that aren't collected can't be breached. Participants have no credentials to steal because none were ever created. Organisers use Sign in with Google or Apple, which is more secure than a password created for a small app. Events stay on your phone unless you sign in or share them.