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What is an Access Key?

The access key (clave de acceso) is a unique 49-digit numeric identifier required for all electronic documents submitted to Ecuador’s SRI. It serves as a unique fingerprint for each invoice and is used throughout the authorization process.
Open Factura automatically generates valid access keys when you use the generateInvoice() function.

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Access Key Structure

The access key is composed of 49 digits organized in the following segments:
SegmentLengthDescriptionExample
Date8 digitsEmission date (DDMMYYYY)01122024
Document Type2 digitsType of document01
RUC13 digitsTax identification number1234567890001
Environment1 digitTesting (1) or Production (2)1
Establishment3 digitsEstablishment code001
Emission Point3 digitsPoint of emission001
Sequential9 digitsSequential document number000000001
Numeric Code8 digitsRandom verification code12345678
Emission Type1 digitEmission type (always 1)1
Verification Digit1 digitModulo 11 checksum7
Total: 49 digits

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Generation Process

Open Factura generates access keys using the generateAccessKey() function defined in src/utils/utils.ts:21.

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Input Parameters

export type GenerateAccessKey = {
  date: Date;
  codDoc: "01" | "03" | "04" | "05" | "06" | "07";
  ruc: string;
  environment: "1" | "2";
  establishment: string;
  emissionPoint: string;
  sequential: string;
};

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Generation Steps

The access key is generated following these steps:

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1. Format the Date

Convert the emission date to DDMMYYYY format: 
function formatDateToDDMMYYYY(date: Date) {
  let day = date.getDate();
  let month = date.getMonth() + 1; // getMonth() returns 0-11
  let year = date.getFullYear();

  // Pad day and month with a leading zero if they are less than 10
  const finalDay = day < 10 ? "0" + day : day;
  const finalMonth = month < 10 ? "0" + month : month;

  return `${finalDay}${finalMonth}${year}`;
}

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2. Concatenate Base Components

The first 41 digits are built by concatenating: 
let accessKey = "";
accessKey += formatDateToDDMMYYYY(accessKeyData.date); // 8 digits
accessKey += accessKeyData.codDoc; // 2 digits
accessKey += accessKeyData.ruc; // 13 digits
accessKey += accessKeyData.environment; // 1 digit
accessKey += accessKeyData.establishment; // 3 digits
accessKey += accessKeyData.emissionPoint; // 3 digits
accessKey += accessKeyData.sequential; // 9 digits
accessKey += generateRandomEightDigitNumber(); // 8 digits
accessKey += "1"; // 1 digit (emission type)

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3. Generate Random Numeric Code

An 8-digit random number is generated for additional uniqueness: 
function generateRandomEightDigitNumber(): number {
  const min = 10000000;
  const max = 99999999;
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

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4. Calculate Verification Digit

The final digit is calculated using the Modulo 11 algorithm: 
function generateVerificatorDigit(accessKey: string) {
  let result = 0;
  let addition = 0;
  let multiple = 7;
  
  // Multiply each digit by a factor from 7 to 2 (cycling)
  for (let i = 0; i < accessKey.length; i++) {
    addition += parseInt(accessKey.charAt(i)) * multiple;
    multiple > 2 ? multiple-- : (multiple = 7);
  }
  
  // Calculate modulo 11
  result = 11 - (addition % 11);
  
  // Handle special cases
  result === 10 ? (result = 1) : (result = result);
  result === 11 ? (result = 0) : (result = result);
  
  return result;
}
The verification digit algorithm multiplies each digit by a factor cycling from 7 down to 2, calculates the sum modulo 11, and applies special rules for values of 10 and 11.

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Complete Generation Function

Here’s the complete access key generation function from src/utils/utils.ts:21: 
export function generateAccessKey(accessKeyData: GenerateAccessKey) {
  let accessKey = "";
  accessKey += formatDateToDDMMYYYY(accessKeyData.date);
  accessKey += accessKeyData.codDoc;
  accessKey += accessKeyData.ruc;
  accessKey += accessKeyData.environment;
  accessKey += accessKeyData.establishment;
  accessKey += accessKeyData.emissionPoint;
  accessKey += accessKeyData.sequential;
  accessKey += generateRandomEightDigitNumber();
  accessKey += "1";
  accessKey += generateVerificatorDigit(accessKey);
  return accessKey;
}

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Example

Let’s generate an access key for an invoice: Input Data:
  • Date: December 1, 2024
  • Document Type: 01 (Invoice)
  • RUC: 1234567890001
  • Environment: 1 (Testing)
  • Establishment: 001
  • Emission Point: 001
  • Sequential: 000000001
  • Random Code: 45678901 (generated)
Resulting Access Key: 
0112202401123456789000110010010000000014567890117
Breakdown:
  • 01122024 - Date (01/12/2024)
  • 01 - Invoice
  • 1234567890001 - RUC
  • 1 - Testing environment
  • 001 - Establishment
  • 001 - Emission point
  • 000000001 - Sequential
  • 45678901 - Random code
  • 1 - Emission type
  • 7 - Verification digit

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Usage in Open Factura

The generateInvoice() function automatically creates the access key: 
import { generateInvoice } from "open-factura";

const { invoice, accessKey } = generateInvoice({
  infoTributaria: {
    ambiente: "1",
    tipoEmision: "1",
    ruc: "1234567890001",
    codDoc: "01",
    estab: "001",
    ptoEmi: "001",
    secuencial: "000000001",
    // claveAcceso is NOT required - it's auto-generated
    // ...
  },
  infoFactura: {
    fechaEmision: "01/12/2024",
    // ...
  },
  // ...
});

// Access key is returned and automatically included in invoice
console.log(accessKey); // "0112202401123456789000110010010000000014567890117"
console.log(invoice.factura.infoTributaria.claveAcceso); // Same value
The access key must be unique for each document. Never reuse access keys, even for corrected or modified invoices.

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Document Type Codes

The codDoc parameter specifies the document type:
  • 01 - FACTURA (Invoice)
  • 03 - LIQUIDACIÓN DE COMPRA DE BIENES Y PRESTACIÓN DE SERVICIOS
  • 04 - NOTA DE CRÉDITO (Credit Note)
  • 05 - NOTA DE DÉBITO (Debit Note)
  • 06 - GUÍA DE REMISIÓN (Delivery Guide)
  • 07 - COMPROBANTE DE RETENCIÓN (Withholding Receipt)

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Environment Types

The environment code indicates where the document will be processed:
  • 1 - Testing (Pruebas): Use for development and testing
  • 2 - Production (Producción): Use for actual business operations
You must enable the testing or production environment in your SRI account before submitting documents. See the SRI Endpoints documentation for activation instructions.

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Best Practices

  1. Sequential Control: Maintain strict control over sequential numbers to avoid duplicates
  2. Date Accuracy: Always use the actual emission date - this cannot be changed later
  3. Environment Matching: Ensure the environment in the access key matches the SRI endpoint you’re using
  4. Storage: Store the access key with your invoice records for future reference and authorization checks

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Next Steps

Invoice Structure

Learn about the complete invoice data structure

SRI Endpoints

Configure endpoints for document submission

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