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WHOIS ARS Phase 1 Overall Results Summary

This page provides high level results and sample design summary of the Phase 1 Syntax Accuracy report. For the full report, see here. For additional result summaries for Phase 1, see here.

Phase 1 Findings

Phase 1 findings show the rates of syntax accuracy (Phase 2 looks at both syntax and operability accuracy) of WHOIS contact information over several dimensions, focusing on rates of conformance by contact mode (Email, Telephone or Post) to the requirements of RAAs (2009 RAA or 2013 RAA). Our analysis finds that approximately 99 percent of email addresses, 85 percent of telephone numbers, and 79 percent of postal addresses met all of the baseline syntax requirements of the 2009 RAA, as shown in the table below.




Postal Address

ALL 3 Accurate

All 3 Contacts Accurate

99.2% ± 0.2%

85.8% ± 0.7%

79.1% ± 0.8%

70.3% ± 0.9%


Regarding the individual contact modes, we can make the following general observations: 

  • If an email is provided, it always passed all syntax accuracy tests
  • Two-thirds of the telephone numbers that failed at least one syntax accuracy check (13 percent of all telephone numbers) failed the length criteria for the applicable country
  • Postal addresses that failed at least one syntax accuracy check (23 percent of all postal addresses) were typically missing at least one required field such as postal code, state, city, or street

Phase 1 Sampling Design

A two-stage sampling method (initial –> analyzed subsample) was designed to provide a large enough sample to reliably estimate subgroups of interest, such as ICANN region, New gTLD or Prior gTLD, and RAA type. The initial sample contained nearly 100,000 records and the analyzed subsample contained 10,000 records representing all 610 active gTLDs at the time of the report. The results from the subsample testing are used to estimate the results for the entire gTLD population or the particular subgroup of interest. Based on sampling error, there is a 95 percent chance that the true parameter (e.g., the percentage of all administrative telephone numbers with a North American registrant that pass all syntax accuracy tests) is within the 95 percent confidence interval.