#503

Document Intelligence

Upload an invoice, receipt, PO or quotation (PDF, text or image) and get its type, fields, line items and checks.

Technique: Keyword classifier + field extractors + arithmetic validation; PDFBox for PDF text

Read the code: src/main/java/com/study/advlab/docintel/DocumentAnalyzer.javasrc/main/java/com/study/advlab/docintel/SampleDocuments.java

1. Document type

INVOICE

Sample: Invoice · text

INVOICE 100%

RECEIPT 0%

PURCHASE ORDER 0%

QUOTATION 0%

CONTRACT 0%

2. Extracted fields 14 found

Field	Value	Confidence	Line
Document number	INV-2026-1187	90%	7
Document date	12/10/2026	90%	8
Due / valid until	11/11/2026	90%	9
Customer / bill to	Northwind Digital Co., Ltd.	85%	10
Vendor / from	BRIGHTWAVE SUPPLIES CO., LTD.	60%	1
Tax ID	0105561234560	95%	3
E-mail	billing@brightwave.co.th	98%	4
Phone	02-123-4567	90%	4
Payment terms	30 days	85%	11
Currency	THB	80%	19
Subtotal	28270.00	90%	17
VAT / tax	1978.90	90%	18
Total	30248.90	90%	19
VAT rate	7 %	95%	18

Line items

Description	Qty	Unit price	Amount
Monitor 27 inch	2	7,900.00	15,800.00
Desk lamp LED	4	1,250.00	5,000.00
USB-C dock	3	2,490.00	7,470.00

3. Validation 8 of 8 checks passed

Line: Monitor 27 inch
2 x 7900.00 = 15800.00 (document says 15800.00)
Line: Desk lamp LED
4 x 1250.00 = 5000.00 (document says 5000.00)
Line: USB-C dock
3 x 2490.00 = 7470.00 (document says 7470.00)
Items add up to the subtotal
Items 28270.00 vs subtotal 28270.00
Subtotal + VAT = total
28270.00 + 1978.90 = 30248.90 (document says 30248.90)
VAT is 7% of the subtotal
Expected 1978.90, document says 1978.90
Due date is after the document date
2026-10-12 -> 2026-11-11
Thai tax ID checksum
13 digits, check digit correct

Source text highlighted lines were used

1BRIGHTWAVE SUPPLIES CO., LTD.

288 Sukhumvit Road, Khlong Toei, Bangkok 10110

3Tax ID: 0105561234560

4Tel: 02-123-4567 billing@brightwave.co.th

6TAX INVOICE

7Invoice No: INV-2026-1187

8Invoice date: 12/10/2026

9Due date: 11/11/2026

10Bill to: Northwind Digital Co., Ltd.

11Payment terms: 30 days

131. Monitor 27 inch 2 x 7,900.00 = 15,800.00

142. Desk lamp LED 4 x 1,250.00 = 5,000.00

153. USB-C dock 3 x 2,490.00 = 7,470.00

17Subtotal: 28,270.00

18VAT 7%: 1,978.90

19Total: 30,248.90 THB

Document	Type	Confidence	Checks	When
Sample: Invoice	INVOICE	100%	8/8	09 Nov 21:16
Sample: Contract (no numbers)	CONTRACT	100%	0/0	09 Nov 20:56
Sample: Receipt	RECEIPT	98%	6/6	09 Nov 20:56
Sample: Quotation	QUOTATION	100%	7/7	09 Nov 20:56
Sample: Invoice	INVOICE	100%	8/8	09 Nov 20:56
Sample: Purchase order	PURCHASE_ORDER	99%	6/6	09 Nov 20:56
Sample: Quotation	QUOTATION	100%	7/7	09 Nov 20:39
Sample: Receipt	RECEIPT	98%	6/6	09 Nov 20:39