# Rf creditor reference compute

`rf-creditor-reference-compute` · version 1.0.0 · Identifiers & check digits · free, no key needed

Compute the MOD 97-10 check digits and full ISO 11649 RF Creditor Reference for a base reference (invoice number).

**Use when you need to: generate an rf creditor reference from an invoice number · compute check digits for a structured reference · build an iso 11649 reference.**

## Decide before calling

Read the [versioned contract](/v1/tools/rf-creditor-reference-compute/versions/1.0.0) and the supported scope below. Reuse `rf-creditor-reference-compute@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation.

## Explain the choice

"I can use `rf-creditor-reference-compute@1.0.0` for generate an rf creditor reference from an invoice number. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

## Supported

- generate an rf creditor reference from an invoice number
- compute check digits for a structured reference
- build an iso 11649 reference
- create a payment reference for a sepa transfer
- turn an order number into a structured creditor reference
- יצירת מספר אסמכתא מובנה לחשבונית

## Not supported

- validating a full reference that may already be wrong (use rf-creditor-reference-validate)
- Swiss QR-bill references (swiss-qr-reference-validate checks them; computing one is not covered)
- case-folding or space-stripping the input

## Behavior

- base_reference is taken exactly as given; this tool does not case-fold or strip spaces. It must already match ^[A-Z0-9]+$, 1-21 characters, or the call throws invalid_input.
- MOD 97-10 check: rearranged = base_reference + 'RF00' (the literal letters R, F, then placeholder check digits '00'). digits = alnum_to_digits(rearranged). r = digits mod 97. check_digits = 98 - r (range 02-98; r = 0 gives '98', never '00'), zero-padded to 2 decimal digits.
- reference = 'RF' + check_digits + base_reference (electronic form, no spaces). print = reference split into groups of 4 characters joined by a single space. Pure string parsing and MOD 97 arithmetic; no pinned dataset.

## Input

- `base_reference` (string, required): min length 1; max length 21; pattern `^[A-Z0-9]+$`

## Output

- `reference` (string, required): min length 5; max length 25
- `check_digits` (string, required): pattern `^[0-9]{2}$`
- `print` (string, required): min length 5; max length 31

## Limits

- max base reference bytes: 21

## Example

Request input:

```json
{
  "base_reference": "539007547034"
}
```

Response:

```json
{
  "result": {
    "reference": "RF18539007547034",
    "check_digits": "18",
    "print": "RF18 5390 0754 7034"
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "rf-creditor-reference-compute",
  "version": "1.0.0",
  "input": {
    "base_reference": "539007547034"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/rf-creditor-reference-compute/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"base_reference":"539007547034"}'
```

The machine-readable contract is at [/v1/tools/rf-creditor-reference-compute/versions/1.0.0](/v1/tools/rf-creditor-reference-compute/versions/1.0.0).

### CLI

```sh
node cli.mjs run rf-creditor-reference-compute 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [Rf creditor reference validate](/tools/rf-creditor-reference-validate): Validate an RF Creditor Reference's ISO 11649 shape and MOD 97-10 check digits, and parse its base reference.
- [Iban compute from bban](/tools/iban-compute-from-bban): Compute the MOD 97-10 check digits and full IBAN for a country code and BBAN, using the pinned IBAN registry.
- [Isin compute from nsin](/tools/isin-compute-from-nsin): Build a 12-character ISIN from a country prefix and a CUSIP/SEDOL national number, computing its Luhn check digit.
- [Checkdigit compute](/tools/checkdigit-compute): Compute the check digit(s) for a payload under a named algorithm (Luhn, Verhoeff, Damm, ISO 7064, GS1, mod 10).
- [Iso6346 container validate](/tools/iso6346-container-validate): Validate an 11-character ISO 6346 container number's mod-11 check digit and split the owner code, category and serial.
- [Checkdigit validate](/tools/checkdigit-validate): Validate a full value's trailing check digit(s) against a named algorithm (Luhn, Verhoeff, Damm, ISO 7064, GS1, mod 10).