ING Kontoauszug Parser

A Ruby gem for parsing ING Bank (Germany) statement PDFs and text exports into structured JSON.

Why This Gem?

ING Germany provides account statements as PDFs, but extracting transaction data programmatically is challenging:

PDF text extraction is messy – Column alignment, page breaks, and OCR artifacts make raw text unreliable
No official export API – ING doesn't provide a machine-readable format like CSV or OFX
Manual categorization is tedious – Hundreds of transactions need consistent tagging for budgeting

This gem solves these problems by:

Extracting clean text from statement PDFs using poppler (fast) or pdf-reader (portable)
Parsing transactions into structured data with dates, amounts, recipients, and narratives
Extracting SEPA metadata like mandate IDs and references for reconciliation
Validating IBANs using the ISO 13616 checksum algorithm
Detecting payment methods like Google Pay for automatic categorization

Use it to build budgeting tools, import transactions into accounting software, or automate expense tracking.

Installation

# Gemfile
gem 'ing_kontoauszug_parser'

bundle install

Quick Start

require 'ing_kontoauszug_parser'

parser = IngKontoauszugParser::StatementParser.new
result = parser.parse(file_path: 'statement.pdf')

result[:header][:iban]              # => "DE89 3704 0044 0532 0130 00"
result[:statements].first[:amount_eur_numeric]  # => "-31.49"

API

parser = IngKontoauszugParser::StatementParser.new

# Parse PDF file
result = parser.parse(file_path: 'statement.pdf')

# Parse text export
result = parser.parse_text(File.read('export.txt'))

# Parse pre-split lines
result = parser.parse_lines(lines)

# Parse booking lines only (no header)
statements = parser.parse_statement_lines(lines)

Output Format

{
  "header": {
    "iban": "DE89 3704 0044 0532 0130 00"
  },
  "statements": [
    {
      "booking_date": "01.08.2025",
      "transfer_type": "Lastschrift",
      "recipient": "Allianz Direct Vers.",
      "amount_eur": "-31,49",
      "amount_eur_numeric": "-31.49",
      "amount_direction": "debit",
      "value_date": "01.08.2025",
      "narrative": "Versicherungsbeitrag August",
      "mandate_id": "MA123456",
      "reference": "RF123456789",
      "google_pay": true
    }
  ]
}

Statement Fields

Field	Type	Description
`booking_date`	string	Booking date (dd.mm.yyyy)
`transfer_type`	string	Transaction type (e.g., Lastschrift, Gutschrift)
`recipient`	string	Counterparty name
`amount_eur`	string	Original amount with German formatting
`amount_eur_numeric`	string	Normalized decimal (BigDecimal as string)
`amount_direction`	string	`debit`, `credit`, or `neutral`
`value_date`	string	Value date (dd.mm.yyyy)
`narrative`	string	Transaction details
`mandate_id`	string?	SEPA mandate ID (if present)
`reference`	string?	SEPA reference or ARN (if present)
`google_pay`	boolean?	`true` if Google Pay detected

CLI Tools

# Parse PDF statement to JSON
bin/pdf_to_json statement.pdf

# Write to file instead of stdout
bin/pdf_to_json -o output.json statement.pdf

# Interactive console
bin/console

Error Handling

PDF reader errors are wrapped as IngKontoauszugParser::Error:

begin
  parser.parse(file_path: 'encrypted.pdf')
rescue IngKontoauszugParser::Error => e
  puts e.message
end

Non-fatal issues (e.g., statements missing value dates) are collected in an optional warnings array:

result = parser.parse_text(text)
result[:warnings]&.each { |w| puts "Warning: #{w}" }

Development

bin/setup      # Install dependencies
rake test      # Run tests
rake rubocop   # Lint