# Update Expense

`lawmatics_update-expense` · Lawmatics MCP tool · Expenses

Update an existing expense in Lawmatics by ID. Supports changing the description and billable flag. Lawmatics requires the matter/contact association on every update, so exactly one of matterId/contactId must be provided — pass the expense's current owner (from get-expense) to keep it unchanged, or a different one to re-target. Note: for contact-attached updates Lawmatics may report a temporary error even though the update WAS applied — verify with get-expense before retrying.

## Input

- **expenseId** `string` (required, pattern: ^\d+$) — ID of the expense to update; a numeric string
- **description** `string` — New description of the expense
- **billable** `boolean` — Whether the expense is billable
- **matterId** `string` — ID of the matter to attach this expense to. Lawmatics requires the matter/contact association on every update — pass the current owner to keep it unchanged
- **contactId** `string` — ID of the contact to attach this expense to. Lawmatics requires the matter/contact association on every update — pass the current owner to keep it unchanged

## Output

- **id** `string` (required) — Unique ID of the updated expense
- **description** `string | null` (required) — Description of the expense; null if unset
- **costCents** `number | null` (required) — Expense cost in integer cents (e.g. 50000 = $500.00); null if not reported
- **billable** `boolean | null` (required) — Whether the expense is billable; null if not reported
- **rateFlatFee** `boolean | null` (required) — Whether the expense is billed as a flat fee; null if not reported
- **rateCents** `number | null` (required) — Billing rate in integer cents; null if not reported
- **rateCurrency** `string | null` (required) — ISO currency code of the billing rate (e.g. USD); null if not reported
- **duration** `number | null` (required) — Duration value as returned by the API (expenses share Lawmatics' time-entry storage model); null if not reported
- **durationRounded** `number | null` (required) — Duration rounded to the firm's billing increment; null if not reported
- **startedAt** `string | null` (required) — ISO 8601 timestamp the expense timer started; null if unset or omitted
- **completedAt** `string | null` (required) — ISO 8601 timestamp the expense timer completed; null if unset or omitted
- **createdAt** `string | null` (required) — When the expense was created, as an ISO 8601 timestamp; null if unknown
- **updatedAt** `string | null` (required) — When the expense was last updated, as an ISO 8601 timestamp; null if unknown
- **relationships** `object` (required) — JSON:API relationship pointers to related records as {id,type} stubs. Not materialized — follow a pointer by calling that resource's own get/find tool (e.g. type 'user' -> get-user, type 'prospect' -> get-matter, type 'contact' -> get-contact, type 'invoice' -> get-invoice).
  - **staff** `object | null` (required) — Pointer to the firm user the expense is attributed to; null when unattributed
    - **id** `string` (required) — ID of the referenced Lawmatics record
    - **type** `string` (required) — JSON:API record class of the reference (e.g. "user", "contact", "prospect", "firm"); resolve it by calling that resource's own get/find tool — this pointer is not materialized
  - **createdBy** `object | null` (required) — Pointer to the firm user who created the record; null when unattributed
    - **id** `string` (required) — ID of the referenced Lawmatics record
    - **type** `string` (required) — JSON:API record class of the reference (e.g. "user", "contact", "prospect", "firm"); resolve it by calling that resource's own get/find tool — this pointer is not materialized
  - **expenseType** `object | null` (required) — Pointer to the billing expense type categorizing this expense; null when uncategorized
    - **id** `string` (required) — ID of the referenced Lawmatics record
    - **type** `string` (required) — JSON:API record class of the reference (e.g. "user", "contact", "prospect", "firm"); resolve it by calling that resource's own get/find tool — this pointer is not materialized
  - **contactable** `object | null` (required) — Pointer to the record the expense is attached to; type is "prospect" for a matter or "contact" for a contact; null when unattached
    - **id** `string` (required) — ID of the referenced Lawmatics record
    - **type** `string` (required) — JSON:API record class of the reference (e.g. "user", "contact", "prospect", "firm"); resolve it by calling that resource's own get/find tool — this pointer is not materialized
  - **invoice** `object | null` (required) — Pointer to the invoice this expense is billed on; null when uninvoiced
    - **id** `string` (required) — ID of the referenced Lawmatics record
    - **type** `string` (required) — JSON:API record class of the reference (e.g. "user", "contact", "prospect", "firm"); resolve it by calling that resource's own get/find tool — this pointer is not materialized