Country code1 published destination

Calling code +81

Calling code +81 routes to Japan.

Guide

How Country Calling Codes Work

Understand the ITU-T E.164 numbering plan and how country codes are assigned and dialed.

6 min read

Guide

ISO Country Codes Explained

The difference between ISO alpha-2, alpha-3, and numeric codes and when to use each one.

5 min read

Guide

How to Dial Internationally

A practical sequence for dialing international numbers from any phone.

4 min read

Guide

What Is a Country Code?

A plain-language introduction to country codes, including calling codes, ISO codes, and ccTLDs.

4 min read

Guide

What Is a ccTLD?

Understand country-code top-level domains and why .uk, .de, and .jp differ from generic domains.

4 min read

Guide

How Time Zones Work

A practical guide to UTC offsets, IANA time zone identifiers, and daylight saving time.

5 min read

Guide

IATA vs. ICAO Airport Codes

Learn the difference between three-letter IATA codes and four-letter ICAO codes used at airports.

5 min read

Guide

How Postal Codes Work Around the World

A country-level guide to postal and ZIP code formats, examples, and validation patterns.

5 min read