# Payment schedules > For the complete machine-readable documentation index, see [llms.txt](https://apidocs.chargebee.com/llms.txt). Payment schedules for an invoice refer to a payment structure where the `amount_due` on an invoice is divided into smaller, more manageable parts, each of which is paid over a specified period. `reference_transactions[]` lists the payment attempts referenced against those installments. ## Sample Payment schedule ```json { "payment_schedule": { "id": "16BdWdUNYtQf97w", "scheme_id": "16Bk0DUNYt3kk3n", "entity_type": "invoice", "entity_id": "a0920247004", "amount": 40000, "currency_code": "USD", "created_at": 1725593728, "updated_at": 1725593800, "resource_version": 1725593800000, "object": "payment_schedule", "schedule_entries": [ { "id": "16BdWdUNYtQfC7x", "date": 1725593728, "amount": 0, "scheduled_amount": 13333, "status": "paid", "object": "schedule_entry" }, {..} ], "reference_transactions": [ { "schedule_entry_id": "16BdWdUNYtQfC7x", "applied_amount": 13333, "txn_id": "txn_16BdWdUNYtQgPay", "txn_status": "success", "txn_date": 1725593800, "txn_amount": 13333 }, {..} ] } } ``` ## Payment schedules attributes ## Input Parameters - `id` (required, string, max chars=40) An auto-generated unique identifier for the payment schedule. - `scheme_id` (required, string, max chars=40) The identifier of the `payment_schedule_scheme` , used to create the payment schedules. - `entity_type` (required, enumerated string) Specifies the types of entity this payment schedule is based on. Possible enum values: - `invoice` Indicates the invoice entity type - `entity_id` (required, string, max chars=50) The identifier of the entity this payment schedule is based on. - `amount` (optional, in cents, min=0) The part of the `invoice.amount_due` to be distributed across the payment schedules. If not specified, the entire `invoice.amount_due` is considered by default. - `created_at` (required, timestamp(UTC) in seconds) The timestamp at which the `payment_schedule` was created. - `resource_version` (optional, long) Version number of this resource. The `resource_version` is updated with a new timestamp in milliseconds for every change made to the resource. This attribute will be present only if the resource has been updated after 2016-09-28. - `updated_at` (optional, timestamp(UTC) in seconds) Specifies when these payment schedules are updated recently. - `currency_code` (optional, string, max chars=3) The currency code (ISO 4217 format) of the transaction amount. - `schedule_entries` (optional, list of schedule_entry) List of schedule entries - `id` (required, string, max chars=40) An auto-generated unique identifier for the payment schedules. - `date` (required, timestamp(UTC) in seconds) Date at which this payment schedule is scheduled. - `amount` (required, in cents, min=0) The remaining amount due on this schedule entry. Decreases as payments are applied. When this value reaches `0`, `status` is `paid`. - `scheduled_amount` (required, in cents, min=0) The original installment amount for this schedule entry. This value does not change when payments are applied. - `status` (required, enumerated string) Defines the status for each payment schedule. Possible enum values: - `posted` The installment is unpaid or partially paid and the due date (`date`) has not passed. - `payment_due` The installment is unpaid or partially paid and the due date (`date`) has passed. - `paid` The installment has been paid. - `reference_transactions` (optional, list of schedule_entry_transaction) The list of transactions referenced against the schedule entries of this payment schedule, most recent first. A transaction referenced against more than one schedule entry appears once per entry. - `schedule_entry_id` (required, string, max chars=40) The identifier of the [`schedule_entries[]`](/docs/api/payment_schedules/payment_schedule-object#schedule_entries) item this transaction is linked to. - `applied_amount` (optional, in cents, min=0) The amount of this transaction applied to this schedule entry. `0` for failed and in-progress transactions until the payment settles. - `txn_id` (required, string, max chars=40) Uniquely identifies the transaction. - `txn_status` (optional, enumerated string) The status of this transaction. Possible enum values: - `in_progress` Transaction is being processed by the gateway. This typically happens for [direct debit transactions](https://www.chargebee.com/docs/direct-debit-payments.html) or, in case of cards, refund transactions. Such transactions can take 2-7 days to complete, depending on the gateway and payment method. - `success` The transaction is successful. - `voided` The transaction got voided or authorization expired at gateway. - `failure` Transaction failed. Refer the 'error\_code' and 'error\_text' fields to know the reason for failure - `timeout` Transaction failed because of Gateway not accepting the connection. - `needs_attention` When connection with the Gateway gets terminated abruptly. For `needs_attention` status Chargebee automatically reconcile the transaction for few gateways, for rest of the gateways you have to use the [Reconcile transaction API](/docs/api/transactions/reconcile-transaction). You can use this API to update the `id_at_gateway` (Gateway Transaction ID) and `status` for a [`needs_attention`](/docs/api/transactions/transaction-object#status) transaction to be reconciled at par with the gateway. [Learn more](https://www.chargebee.com/docs/payments/2.0/needs-attention-transactions.html) about `needs_attention` transaction status - `late_failure` Indicates that a successful payment transaction has failed now due to a late failure notification from the payment gateway, typically caused by issues like insufficient funds or a closed bank account. - `txn_date` (optional, timestamp(UTC) in seconds) Indicates when this transaction occurred. - `txn_amount` (optional, in cents, min=0) Total amount of the transaction.