# Constraints for correspondences and payment methods

Default settings: All correspondences, except of invoices, are sent by Ratepay per default. All correspondences, except of `dunning_3` are sent in shop branding.

The following correspondences can be configured for the different payment methods:

| Ratepay payment method | payment_option | transfer_type | Possible correspondences |
|  --- | --- | --- | --- |
| Open Invoice | `OPEN_INVOICE` | `BANK_TRANSFER` | `invoice``payment_instruction``payment_receipt``dunning_1``dunning_2``dunning_3` |
| Direct Debit | `OPEN_INVOICE` | `DIRECT_DEBIT` | `advance_notice``invoice``dunning_1``dunning_2``dunning_3` |
| Instalment Bank Transfer | `INSTALMENT` | `BANK_TRANSFER` | `order_confirmation``invoice``initial_plan``updated_plan``dunning_1``dunning_2``dunning_3` |
| Instalment Direct Debit | `INSTALMENT` | `DIRECT_DEBIT` | `advance_notice_sepa_update``order_confirmation``invoice``initial_plan``updated_plan``dunning_1``dunning_2``dunning_3` |
| Prepayment | `PREPAYMENT` | `BANK_TRANSFER` | `invoice``payment_instruction``payment_receipt` |