Personal + household budgets
Split your income into personal categories and a household contribution. Shared money is funded by everyone and planned together.
Household budgeting, together
Plan the month. Split the bills. Settle up.
project-b replaces the notes-app ritual: everyone budgets their month, logs what they spend, and the household sees exactly who owes whom — no spreadsheet, no arguments.
Free to use. No bank connection — you stay in control of the money.
Features
Everything a shared household needs
Personal money and shared money, side by side — with the month-end maths done for you.
Log an expense in seconds
Payer, category, amount, memo. Record it while you're still at the till — household, personal, or fronted for someone else.
IOUs, tracked properly
Fronted a partner's expense? It becomes an IOU with a name and an amount, and it clears itself when the month is settled.
Month-end settlement
At the end of the month, see who owes whom — with the split rule (equal, proportional, or custom) already applied.
Monthly report, exportable
A month-by-month view of what you planned versus what you spent, ready to export as a PDF when you need a record.
Built for more than two
Invite anyone with a code. Budget history is versioned, so a change mid-month never rewrites what already happened.
How it works
Set up once, then just log and settle
A short guided setup gets your household, categories and budgets in place. After that it's one tap per expense.
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1
Start or join a household
Create your household, or enter the invite code someone already shared with you.
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2
Split your income
Decide how much of each month goes to the shared pot versus your own categories, then plan the household budget together.
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3
Log, then settle
Record expenses as they happen. At month end the report shows what you spent and who owes whom.
FAQ
Questions, answered
Does it connect to my bank?
No. You enter expenses yourself, and the app never asks for bank credentials or account numbers. How the money actually moves is your call.
How many people can share a household?
As many as you like. project-b is designed for the common two-person home but the model supports any number of members.
What currency does it use?
Japanese yen, as whole numbers — no decimals to round away and no conversion.
Can I delete my account?
Yes, at any time from Settings in the app. Your account, household memberships and stored data are permanently removed.
Start your household budget
Set up your household in a few minutes — free, no card, no bank connection.