> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/vivekbw/divvy/llms.txt
> Use this file to discover all available pages before exploring further.

# Expenses

> Add, track, and manage shared expenses within your groups

## Overview

Expenses represent purchases or costs that need to be split among group members. Every expense records who paid, how much, and how it's divided.

## Creating an Expense

To add a new expense to a group:

1. Open a group from your Groups list
2. Tap **Add New Expense**
3. Enter the total amount in dollars
4. Add a description (e.g., "Dinner at Maple Bistro", "Groceries")
5. Select who paid for the expense
6. Choose a split method (see [Split Methods](/features/split-methods))
7. Select which group to add it to
8. Tap **Add expense** to save

<Info>
  If you scanned a receipt, the amount and description will be pre-filled automatically.
</Info>

## Expense Fields

Each expense includes:

### Amount

Enter the total cost in dollars and cents. The large currency input makes it easy to enter amounts quickly:

```
$ 47.50
```

The amount must be greater than \$0.00 to create the expense.

### Description

A short label to identify the expense (e.g., merchant name, event, or category). If left blank, it defaults to "Expense".

### Paid By

Select who fronted the money for this purchase. Options include:

* **You** (default)
* Any other group member

This determines who should be reimbursed.

### Split Method

Choose how to divide the cost among members. Three options are available:

<CardGroup cols={3}>
  <Card title="Split equally" icon="dollar-sign">
    Everyone pays the same amount
  </Card>

  <Card title="By percentage" icon="percent">
    Custom % for each person
  </Card>

  <Card title="By items" icon="list-check">
    Assign items to people
  </Card>
</CardGroup>

See [Split Methods](/features/split-methods) for detailed workflows.

## Equal Split Preview

When splitting equally, Divvy shows a live preview of the per-person amount:

**Example:** $60.00 split among 3 people = **$20.00 each\*\*

The preview updates instantly as you change the total amount or add/remove members.

## Group Selection

If you belong to multiple groups, select which group this expense belongs to. Each group card shows:

* Group icon
* Group name
* Selection indicator (checkmark when selected)

You can only add an expense to one group at a time.

## Editing Expenses

<Note>
  Currently, expenses cannot be edited after creation. To correct an expense, delete it and create a new one.
</Note>

## Deleting Expenses

Expense deletion is managed through the group activity feed. Contact your group admin if you need to remove an expense.

## Expense Data Model

Expenses are stored with the following structure:

```kotlin theme={null}
data class Expense(
    val id: String,
    val groupId: String,
    val merchant: String,           // Description/merchant name
    val amountCents: Long,          // Total amount in cents
    val splitMethod: String,        // "EQUAL", "PERCENTAGE", or "ITEMIZED"
    val currency: String,           // Default: "USD"
    val paidByUserId: String,       // Who paid upfront
    val createdAt: String           // ISO timestamp
)
```

**Key Details:**

* Amounts are stored in cents to avoid floating-point precision issues
* `splitMethod` determines how the expense is divided (see `~/workspace/source/app/src/main/java/com/example/divvy/ui/splitexpense/ViewModels/SplitExpenseViewModel.kt:27`)
* Each expense is tied to exactly one group via `groupId`

Reference: `~/workspace/source/app/src/main/java/com/example/divvy/models/Expense.kt:7`

## Split Calculation

When you create an expense, Divvy automatically:

1. Calculates each person's share based on the split method
2. Creates `Split` records for each member
3. Updates group balances in real-time
4. Posts an activity item to the group feed

See [Ledger](/features/ledger) to understand how balances are calculated across expenses.