Water Bill OCR

Reads a Thai water bill from MWA or PWA and returns the customer, the readings and the charges.

POST/ocr/v3/water-bill/fileTry it

• Price1 ICper page
• Measured99.5%
• Served29Kcalls

• v1.0
• Active
• Benchmark paper (PDF)

Input

OutputPOST /ocr/v3/water-bill/file

provider

การประปานครหลวง

customer_name

—

customer_address

32/14 ม.3 ตำบลท่าจีน อำเภอสามพราน จังหวัดนครปฐม 11130

account_number

67983262

invoice_number

192011-5

invoice_date

12/02/2567

current_reading

606

previous_reading

567

consumption_cubic_meter

39

water_usage_charge

430.39

monthly_service_fee

25

discount

0

subtotal_before_vat

461.24

vat_amount

32.29

total_amount

493.53

due_date

22/02/2567

Every field, under Response

Request

curl -X POST "https://api.iapp.co.th/ocr/v3/water-bill/file" \
  -H "apikey: YOUR_API_KEY" \
  -F "file=@/path/to/document.pdf" \
  -F "target_lang=th" \
  -F "include_confidence=true"

Response

200OK. The fields are explained under Response.

{
    "docs": [
        {
            "message": "success",
            "raw": {},
            "processed": {
                        "provider": "การประปานครหลวง",
                        "customer_name": null,
                        "customer_address": "32/14 ม.3 ตำบลท่าจีน อำเภอสามพราน จังหวัดนครปฐม 11130",
                        "account_number": "67983262",
                        "invoice_number": "192011-5",
                        "invoice_date": "12/02/2567",
                        "current_reading": 606,
                        "previous_reading": 567,
                        "consumption_cubic_meter": 39,
                        "water_usage_charge": 430.39,
                        "monthly_service_fee": 25.0,
                        "discount": 0.0,
                        "subtotal_before_vat": 461.24,
                        "vat_amount": 32.29,
                        "total_amount": 493.53,
                        "due_date": "22/02/2567"
            },
            "confidence": {
                        "provider": 0.95,
                        "customer_name": 0.95,
                        "customer_address": 0.95,
                        "account_number": 0.95,
                        "invoice_number": 0.95,
                        "invoice_date": 0.95
            },
            "process_ms": 4120
        }
    ],
    "docs_count": 1,
    "process_ms": 4300
}

Request

multipart/form-data only; there is no Base64 form. Every page of a PDF is read and billed.

Headers

apikeystringrequired

Your API key, created under API Keys in the control panel.

Body

filefilerequired

The bill. PDF, JPEG, PNG or WEBP, up to 50 MB. Repeatable: several documents in one request.

return_ocrboolean

true to include the raw OCR text.

target_langstring

The language of the extracted values: th, the default, en, or auto to keep the document's own language.

include_confidenceboolean

Default true: a confidence from 0.00 to 1.00 per field.

/v3/store/ocr/water-bill is the same endpoint under the store prefix.

Response

The iapp-input-pages header carries the number of pages billed.

docsarray

One entry per document read

docs.processedobject

The fields read from the document

docs.processed.providerstring

The issuing authority, for example การประปานครหลวง

docs.processed.customer_namedocs.processed.customer_address

The customer and the service address

docs.processed.account_numberdocs.processed.invoice_numberdocs.processed.invoice_date

The water customer registration number, the bill number and its date

docs.processed.current_readingdocs.processed.previous_readingdocs.processed.consumption_cubic_meter

The two readings and the cubic metres consumed

docs.processed.water_usage_chargedocs.processed.monthly_service_feedocs.processed.discount

The charges, THB

docs.processed.subtotal_before_vatdocs.processed.vat_amountdocs.processed.total_amount

The totals, THB

docs.processed.due_datestring

When payment is due

docs.messagestring

Status message

docs.rawobject

The OCR text, when requested

docs.confidenceobject

Confidence per field, 0 to 1

docs.process_msinteger

Processing time, in milliseconds

docs_countinteger

Number of documents read

process_msinteger

Processing time, in milliseconds

Status codes

Code	Meaning
400	Unsupported file extension, or a file over 50 MB
404	Unknown document type in the URL
422	No file attached
500	Processing error; the response carries a code to quote to support
502	Temporary processing failure, also when any page of a multi-page file fails (code: PROCESSING_FAILED). Not charged; retry
503	Service busy (PROCESSING_BUSY). Not charged; retry, after the seconds in Retry-After when that header is present
504	Processing timed out (PROCESSING_TIMEOUT). Not charged; retry

Details

Measured

On the production service, 28 October 2026, against 40 synthetic Thai water bills: every customer, account and amount invented, every page watermarked "specimen", half degraded as office scans and half as phone photographs.

Measure	Result
Fields exactly right, 610 fields	99.5% (95% CI 98.9–100.0)
Scan / phone photograph	99.0% / 100.0%
Bills with every field right	92.5%
Every other field, including meter readings, consumption, charges, VAT and totals	100.0%
Weakest field: customer address	92.5%
All 11 business-document types in the benchmark, 5,092 fields	97.9%
Median time per page through the API, 44 documents across the 11 types	10.8 s (19.9 s at the 95th percentile)

Every error was in the customer address; check addresses against another source where they matter. Real bills, with stamps, handwriting and low-contrast printing, score lower than this synthetic set. Method and every field: the benchmark (PDF).

Limits

• Up to 50 MB per request.
• Only the fields above are extracted.
• Degraded scans, glare and handwriting over printed values lower accuracy. Prefer the original PDF, a square-on photograph in even light, or a scan at 300 dpi or more.
• The per-field confidence does not mark errors: across the 11 document types in the benchmark it averaged 0.957 on wrong fields and 0.967 on right ones, and 97.4% of wrong fields scored 0.90 or more. Choose fields for review with arithmetic checks (totals, VAT, balances) and identifier check digits instead.

Data handling

Consent and notice under PDPA and GDPR remain with you as the data controller.