# Ledger

Manage double-entry accounting ledger

## List Journal Entries

 - [GET /ledger/journalEntries](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/listjournalentries.md): List journal entries (double-entry accounting records).

Sources:
- INVOICE - Created when invoice is posted (DR: A/R, CR: Revenue)
- PAYMENT - Created when payment is received (DR: Bank, CR: A/R)
- REFUND - Created when refund is processed
- ADJUSTMENT - Manual corrections
- REMITTANCE - Payment processor fee tracking

## Create Journal Entry

 - [POST /ledger/journalEntries](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/createjournalentry.md): Create a new journal entry with lines.

Double-Entry Rule: Sum of debits MUST equal sum of credits.
The entry will be rejected if not balanced.

Immutability: Journal entries are immutable once created.
Use adjustment entries for corrections.

Account Codes:
- REVENUE - Revenue accounts
- AR - Accounts Receivable
- CONTRA_REVENUE - Contra-revenue (discounts)
- CLEARING - Clearing accounts
- BANK - Bank accounts
- FEE_EXPENSE - Processing fee expenses
- REFUND_EXPENSE - Refund expenses

## Get Journal Entry Details

 - [GET /ledger/journalEntries/{journalEntryId}](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/getjournalentry.md): Retrieve details of a specific journal entry including all lines

## Get Account Balances

 - [GET /ledger/accountBalances](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/getaccountbalances.md): Get current balances for all ledger account codes.

Useful for reconciliation and financial reporting.

## Get Trial Balance

 - [GET /ledger/trialBalance](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/gettrialbalance.md): Get trial balance report showing all accounts with their debit and credit totals.

Validation: Debit total should equal credit total.

## Journal Entry Created

 - [POST ledgerJournalEntryCreated](https://docs.nelnetpay.com/apis/billing-ledger-service/ledger/webhookjournalentrycreated.md): Fired when a new journal entry is created.

Use Cases:
- Real-time GL integration
- Audit trail synchronization
- External accounting system updates

Security: Payload is signed with HMAC-SHA256. 
Verify using the X-NPS-Signature header.