✓ TestedWorks with CSV, Excel, Google Sheets → JSON-LD Schema
By dataclean.to team · 2026-02-05
Contractor databases accumulate inconsistent category data from multiple sources: licensing boards, referral networks, customer reviews, and internal records. A roofing contractor might be categorized as "Roofing", "Roof Repair & Installation", "Roofer", or "Roofing Contractor" across different records. dataclean.to identifies these duplicates and merges them into a unified taxonomy.
The Problem
Contractor directories and management platforms pull data from varied sources, each using different naming schemes for trades, specialties, and service areas. Without consistent categories, searching for contractors by specialty returns incomplete results, and reporting on contractor distribution by trade is unreliable. W3C Data on the Web Best Practices for consistent categorization
How to Fix It
1
Upload your contractor data
Export your contractor directory, licensing database, or vendor list to CSV. Include columns for trade categories, specialties, license types, or service classifications.
2
Detect categorical columns
The tool scans your file and identifies columns containing categorical data like trade names, certification types, and service areas. Confirm which columns to normalize.
3
Review trade category clusters
dataclean.to groups similar trade names together. "Plumber", "Plumbing Contractor", "Licensed Plumber", and "Plumbing Services" would be clustered and assigned a single standard label.
4
Refine and approve normalizations
Adjust groupings to match your directory's official trade categories. Split overly broad groups or merge niche specialties as appropriate for your use case.
5
Export the cleaned contractor list
Download the standardized CSV for use in your contractor directory, marketplace, or internal vendor management system.
Frequently Asked Questions
Does this handle multi-trade contractors?
Yes. If a contractor has multiple specialties in one field (e.g., "Plumbing, Heating, Gas Fitting"), the tool can normalize each specialty individually while keeping them associated with the same contractor record.
Can it recognize regional trade terminology?
The normalization engine handles common regional variations, such as "sparky" for electrician in Australian data or "chippy" for carpenter in UK data, mapping them to standard trade names.
What about license type categories?
License types like "Class A", "Class B", "General", and "Specialty" can be normalized alongside trade categories. Each column is processed independently with its own set of normalization rules.
Example: Input → Output
name
email
phone
city
status
Alice Johnson
alice@example.com
+1-555-0101
New York
active
alice johnson
ALICE@EXAMPLE.COM
5550101
new york
Active
Red rows show common data quality issues. dataclean.to normalizes and generates JSON-LD automatically.