Worldwide Country Phone Codes & SIM USSD Codes: International Calling Directory (FR)

Understanding the ITU-T E.164 Global Numbering Standard

Every international telephone call relies on a standardized numbering format governed by the International Telecommunication Union (ITU), a specialized agency of the United Nations. Recommendation ITU-T E.164 establishes the international public telecommunication numbering plan.

An E.164 compliant phone number consists of three distinct parts: the Country Code (CC), the National Destination Code (NDC or area code), and the Subscriber Number (SN). An E.164 number is prefixed with a plus symbol (+) and can have a maximum of 15 digits (excluding the plus symbol). For example, in +44 20 7946 0958, +44 represents the United Kingdom country code, 20 represents the London area code, and 7946 0958 is the unique subscriber line.

The world is divided into nine geographical numbering zones: Zone 1 comprises North America (USA, Canada, Caribbean islands under +1); Zone 2 covers Africa; Zones 3 and 4 encompass Europe (+30 to +49); Zone 5 represents South and Central America; Zone 6 includes Southeast Asia and Oceania (+60 Malaysia, +61 Australia, +62 Indonesia, +65 Singapore, +66 Thailand); Zone 7 covers Russia and Kazakhstan; Zone 8 encompasses East Asia (+81 Japan, +82 South Korea, +84 Vietnam, +86 China, +852 Hong Kong); and Zone 9 covers the Middle East and South Asia (+90 Turkey, +91 India, +92 Pakistan, +966 Saudi Arabia, +971 UAE).

International Dialing Mechanics: Exit Codes, Trunk Prefixes & The Plus Symbol

To place an overseas call, callers historically had to dial an International Direct Dialing (IDD) exit code before dialing the destination country code. In countries following the ITU recommendation (such as the UK, Europe, Australia, India, and China), the IDD code is 00. In the United States and Canada, the IDD code is 011. In Japan, it is 010.

Modern mobile devices and smartphones simplify this through the plus (+) symbol. Long-pressing the "0" key on mobile dialpads produces "+", which instructs the cellular network to automatically inject the correct outbound exit code based on the user's current home or roaming network.

A critical rule of international dialing is dropping the national trunk prefix. In domestic dialing, callers dial a leading zero (0) to signal a long-distance call within their nation (for instance, dialing 020 for London or 081 for Bangkok). When dialing internationally, this leading zero must be removed: +44 20... rather than +44 020..., and +66 81... rather than +66 081.... Failing to drop the leading zero is the number one cause of international connection failures.

Reverse Calling Code Lookup: Identifying Incoming Foreign Phone Numbers

When receiving unexpected calls or text messages starting with an unfamiliar prefix, reverse calling code lookup helps determine the geographic origin before answering or calling back. Common international calling codes include:

• +1: United States, Canada, and North American islands (Jamaica, Bahamas, Puerto Rico, Guam).

• +44: United Kingdom (England, Scotland, Wales, Northern Ireland, Isle of Man, Jersey, Guernsey).

• +61: Australia (including Christmas Island and Cocos Islands).

• +91: India (including all telecom circles from Delhi to Mumbai).

• +86: China (mainland telecommunications network).

• +971: United Arab Emirates (Dubai, Abu Dhabi, Sharjah).

• +966: Saudi Arabia (STC, Mobily, Zain networks).

• +66: Thailand (Bangkok, Phuket, Chiang Mai, Pattaya).

• +49: Germany (Deutsche Telekom, Vodafone, Telefónica O2).

• +33: France (Orange, SFR, Bouygues, Free Mobile).

• +60: Malaysia (Kuala Lumpur, Penang, CelcomDigi, Maxis).

• +62: Indonesia (Jakarta, Bali, Telkomsel, Indosat Ooredoo).

• +81: Japan (NTT Docomo, KDDI au, SoftBank).

• +84: Vietnam (Viettel, Vinaphone, Mobifone).

• +31: Netherlands, +34: Spain, +39: Italy, +41: Switzerland, +353: Ireland, +90: Turkey, +92: Pakistan, +880: Bangladesh.

Mobile SIM & USSD Codes: Unstructured Supplementary Service Data Explained

Unstructured Supplementary Service Data (USSD), commonly called quick codes or feature codes, is a GSM communications protocol used by mobile operators to transmit information between subscribers and network service centers. Unlike SMS messages, USSD creates a real-time, interactive session with zero latency.

USSD codes typically begin with an asterisk (*) and end with a hash/pound sign (#), such as *100#, *121#, or *966#. Because they travel over the mobile signaling channel (SSCH), USSD strings function even when mobile data (4G/5G) is disabled, roaming without an active internet pack, or when the subscriber account balance is zero.

Common categories of essential USSD service codes include:

1. Balance & Airtime Check: Query remaining prepaid credit balance and account validity dates (e.g. AIS Thailand *121#, STC Saudi Arabia *166#, Vodafone UK *#1345#).

2. Internet / Data Quota: Check active 4G/5G gigabyte balance and expiration date (e.g. AIS *121*32#, Jazz Pakistan *117*4*2#, Airtel India *121*1#).

3. Own Number Verification: Instantly display the SIM phone number on the screen when inserting an unfamiliar SIM card or traveling (e.g. TrueMove H *933#, Jazz *99#, EE UK texting NUMBER to 150).

4. Scratch Card Recharge: Top up prepaid credit using a voucher PIN (e.g. *120*VOUCHER_PIN# or *101*PIN#).

5. Emergency Advance Credit: Request a small loan or airtime advance when stranded with zero balance.

6. Call Forwarding & Waiting (MMI): Supplementary hardware codes standardized by 3GPP (e.g., *43# to enable call waiting, ##002# to cancel all call diverts).

Mobile Number Portability (MNP) & Prefix Caveats

Historically, the first few digits of a mobile phone number (the national mobile destination code or mobile prefix) uniquely identified the network provider. For instance, in the UK, 07700 numbers were allocated to specific carriers, while in Saudi Arabia 050 was STC and 056 was Mobily.

However, the worldwide rollout of Mobile Number Portability (MNP) regulations allows subscribers to retain their exact mobile number when switching between competing cellular operators. Therefore, while dialing prefix 081 in Thailand suggests an AIS subscriber, the user may have ported their line to TrueMove H. Telecom databases classify prefixes by original allocation and recommend checking carrier-specific billing rates where applicable.

Step-by-Step Guide: How to Use ToolSphare Country Phone & SIM USSD Finder

ToolSphare provides a free, instant, worldwide telecom search utility to solve phone number verification and carrier code lookup without installing questionable mobile apps.

Step 1 — Search or Auto-Detect Country: Open the tool at toolsphare.tech/en/tools/country-phone-sim-code-finder. Your current country will be detected automatically. You can also search by country name, ISO2/ISO3 code, or calling code (e.g., type "+66" or "Thailand").

Step 2 — Explore Calling Formats & Emergency Numbers: View the country card to inspect the international dial format, national trunk prefix, reverse country code, and emergency contact numbers (Police, Ambulance, Fire).

Step 3 — Access Verified Carrier SIM Codes: Switch to the "SIM & USSD Codes" tab. Select your network operator (such as AIS, STC, Vodafone, Airtel, EE, or Telstra) to view categorized codes for balance inquiry, internet data, own number check, recharge, and customer support.

Step 4 — 1-Click Dial or Copy: Click "Copy Code" to copy the exact dial string, or click "Dial Code" on mobile devices to open your smartphone dialer with RFC 3966 encoding pre-filled.

Step 5 — Validate Phone Numbers (E.164): Switch to the "Phone Number Checker" tab, enter any local or international number, and click Validate. Our libphonenumber engine analyzes validity, detects line type (mobile, fixed-line, toll-free), formats into E.164, and provides time zones and possible carrier origins.