How to Call Cambodia from the US

To call Cambodia from the US, dial 011 + 855 + area code or mobile prefix (drop leading 0) + local number. Phnom Penh example: 011-855-23-XXXXXX. Siem Reap: 011-855-63-XXXXXX. Cambodian mobile: 011-855-88-XXXXXXX (operator prefix such as 010/012/088, no leading 0).

The 011 is the US international exit code. The 855 is Cambodia’s country code. This pattern works from any US landline or mobile — on a smartphone you can substitute + for 011, dialing +855 23 XXXXXX.

How to dial Cambodia from the US

Follow these four steps every time:

1. Dial 011 — the US exit code for all international calls. On a mobile keypad, long-press 0 to enter + as a shortcut; + works identically to 011 on smartphones.
2. Dial 855 — Cambodia’s ITU-assigned country code under the E.164 numbering plan.
3. Dial the area code or mobile prefix without its leading 0. Cambodian numbers in domestic format start with a 0 trunk prefix. That 0 is dropped for international dialing. Phnom Penh’s domestic prefix 023 becomes 23; Siem Reap’s 063 becomes 63.
4. Dial the local subscriber number exactly as written. Total digit count after the country code varies by line type — Cambodian national numbers run roughly 8 to 9 digits.

The complete pattern: 011 855 <prefix minus leading 0> <local number>.

If you see a Cambodian number already formatted with +855 (common on business cards and websites), replace the + with 011 from a US landline, or dial it as-is from a smartphone.

Cambodian area codes by city

Cambodian landlines use geographic area codes tied to provinces. The leading 0 shown in domestic format is dropped for all international calls.

City / Province	Domestic prefix	Dial from US (after 011 855)
Phnom Penh	023	23
Siem Reap	063	63
Sihanoukville	034	34
Battambang	053	53
Kampot	033	33
Takeo	032	32

Cambodian mobile numbers do not use province area codes. Mobile prefixes (after the country code) include 10, 12, 15, 16, 81, 88, 97 and others — assigned to network operators such as Smart, Metfone, and Cellcard. Example: a number beginning 088 is dialed from the US as 011 855 88 XXXXXXX.

How Cambodian numbering works

Cambodia uses a closed national numbering plan with a mandatory 0 trunk prefix for domestic calls.

National numbers run approximately 8 to 9 digits after the trunk prefix. Landlines carry a province area code (such as 023 for Phnom Penh), while mobiles carry a two- or three-digit operator code (such as 012 or 088) instead of a geographic code.

When you call internationally, you replace the leading 0 with the international access sequence: 011 855 from the US, or +855 in E.164 notation. The single rule that covers every Cambodian number is the same — drop the leading 0, then dial the rest.

Because mobile and landline numbers can differ in length, always dial the full subscriber number exactly as your contact provides it, and save it in +855 format to avoid guesswork later.

Time zone: Indochina Time (ICT)

Cambodia operates on a single time zone nationwide:

• ICT (Indochina Time) — UTC+7, in effect all year. Cambodia does not observe daylight saving time.

US time zone	Offset during US daylight saving (Mar–Nov)	Offset during US standard time (Nov–Mar)
Eastern (ET)	Cambodia +11 h	Cambodia +12 h
Central (CT)	Cambodia +12 h	Cambodia +13 h
Mountain (MT)	Cambodia +13 h	Cambodia +14 h
Pacific (PT)	Cambodia +14 h	Cambodia +15 h

Important for business callers: because Cambodia never changes its clocks, the entire offset shift comes from the US side each spring and fall. The gap with US Eastern moves between 11 and 12 hours depending on the season.

The most workable overlap for standard business hours is early morning US Eastern: a call at 8 AM–9 AM ET reaches Cambodia around 7 PM–8 PM ICT, near the end of their working day. To catch mid-day Cambodian hours, schedule for the previous evening in US time.

US to Cambodia calling costs

Costs vary significantly by calling method:

• US carrier per-minute (no plan): major US carriers can charge several dollars per minute to Cambodia without an international add-on. Fine for a rare call, expensive for anything regular.
• Carrier international add-on packages: a monthly fee reduces per-minute rates and is worthwhile above modest monthly volume.
• VoIP providers (including DialPhone): flat per-minute rates to Cambodia that typically undercut carrier add-ons, with no monthly minimum. For US–Cambodia business calling at any volume, a VoIP plan on DialPhone business phone avoids per-minute sticker shock.
• Free app-to-app (WhatsApp, Telegram): works if the Cambodian side also uses the app and has Wi-Fi or data. Telegram in particular is widely used in Cambodia. Not viable for reaching landlines or businesses that do not use the app.

Confirm current per-minute rates with your provider before relying on any single figure — international carrier pricing changes frequently.

Calling Cambodian mobile vs landline from the US

From a US perspective, the dialing procedure is the same: 011 855 <number without leading 0>. The difference lies in the number format itself:

• Landlines carry a geographic province area code (such as 023 or 063) followed by the local subscriber number.
• Mobiles start with an operator prefix (such as 010, 012, 088) and have no province area code. The prefix identifies the carrier, not a location.

Identifying the type from the number: a Cambodian number whose prefix after the leading 0 is a known operator code (10, 12, 15, 16, 81, 88, 97, and similar) is a mobile. A number whose prefix matches a province code (23, 63, 34, 53, and so on) is a landline.

VoIP providers including DialPhone typically apply a single flat rate to Cambodian destinations, simplifying budgeting whether you reach a mobile or a landline.

SMS to Cambodia and business use cases

US-to-Cambodia SMS works from most US mobile plans — the same international add-on that covers calls usually covers texts. Note that messaging apps such as Telegram are heavily used in Cambodia and often the preferred channel for business contact.

Business-grade SMS (A2P, bulk, or CRM-triggered) requires a provider supporting international SMS routing to Cambodian networks.

US–Cambodia B2B context where this matters most:

• Garment and manufacturing sourcing: US apparel and consumer-goods buyers coordinate with Cambodian factories and sourcing agents, where reliable voice contact across an 11–12 hour offset is essential.
• NGO and development work: US-based organizations running programs in Cambodia need dependable two-way contact with field offices in Phnom Penh and the provinces.
• Tourism and hospitality: US travel operators booking Siem Reap and Angkor-area properties benefit from a clear international dialing process and predictable per-minute rates.

For teams managing the wide time-zone gap, a DialPhone AI receptionist can answer inbound calls from Cambodian contacts during their business day — well outside US hours — qualifying and routing the inquiry so nothing is lost to the offset.

For outbound, DialPhone routes US-to-Cambodia calls with consistent caller ID handling and flat per-minute pricing, so an occasional call and a daily-volume workflow cost the same per minute.

FAQ

Calling Cambodia FAQ

What is the country code for Cambodia? +

Cambodia's country code is +855. From a US landline or mobile, you reach it by dialing the US international exit code 011 first, making the full prefix 011 855. From a smartphone that supports E.164 dialing you can substitute + for 011, so +855 works identically.

Do I need to drop the leading 0 when calling Cambodia from the US? +

Yes. Cambodian numbers in domestic format start with a 0 — for example, a Phnom Penh landline is written 023 XXX XXX locally. That leading 0 is Cambodia's trunk prefix and is only used for calls placed inside Cambodia.

When calling from the US, replace the entire leading 0 with 011 855. So 023 123 456 becomes 011 855 23 123 456. Leaving the 0 in is the most common reason a US-to-Cambodia call fails to connect.

How do I call a Cambodian mobile number from the US? +

Cambodian mobile numbers start with a 0 plus a two- or three-digit operator code in domestic format — common prefixes include 010, 012, 015, 016, 081, 088, and 097. Dial 011 + 855 + the mobile number without its leading 0.

Example: a number written as 088 234 5678 is dialed from the US as 011 855 88 234 5678. The operator code identifies the carrier network (Smart, Metfone, Cellcard, and others) rather than a geographic area.

What is the best time to call Cambodia from the US? +

Cambodia observes Indochina Time (ICT), UTC+7 year-round, and does not use daylight saving time. That puts Cambodia 11 hours ahead of US Eastern Time during US daylight saving and 12 hours ahead during US standard time.

The offset makes same-day overlap tight. The most practical window is early morning US Eastern — a call at 8 AM–9 AM ET reaches Cambodia at 7 PM–8 PM ICT, at the end of their working day. For mid-day Cambodian hours, calling the evening before US time works best.

How much does it cost to call Cambodia from the US? +

Standard US carrier rates without an international plan can run several dollars per minute to Cambodia. Carrier international add-on packages reduce this for a monthly fee.

VoIP providers including DialPhone charge flat per-minute rates to Cambodian destinations that are typically lower than carrier add-on plans, with no monthly minimum for low-volume callers. Confirm current rates before relying on any single figure, as carrier pricing changes frequently.

Can I call Cambodian toll-free (1800) numbers from the US? +

Cambodian 1800 freephone numbers are reachable only when dialed from within Cambodia. Calling them from the US will typically fail to connect, because domestic toll-free numbers are tied to local infrastructure and are not routed across international carrier networks.

Ask your Cambodian contact for their geographic +855 landline or a mobile number as a reachable alternative from abroad.

What time zone is Cambodia in and does it change? +

Cambodia uses a single time zone nationwide: Indochina Time (ICT), UTC+7. It applies all year — Cambodia does not observe daylight saving time, so the local offset never shifts.

Because the US does change clocks twice a year, the gap between Cambodia and US time zones moves by one hour each spring and fall. Cambodia is 11 hours ahead of US Eastern in summer and 12 hours ahead in winter — the change comes from the US side, not Cambodia.

How do I save a Cambodian number in my phone contacts? +

Save Cambodian numbers in full E.164 international format: +855 followed by the area code or mobile prefix without its leading 0, then the local number. For example, a Phnom Penh number 023 123 456 should be saved as +855 23 123 456.

This format works from any country without modification, prevents dialing errors when roaming, and is the standard format expected by CRMs and VoIP platforms including DialPhone.

Start calling Cambodia today

Whether you place occasional calls to a Cambodian supplier or run a team with daily US–Cambodia volume, the right setup eliminates per-minute sticker shock and missed calls.

• DialPhone pricing — compare per-minute international rates across plans
• Start a free trial — call Cambodia from day one, no commitment
• DialPhone business phone — full VoIP platform for international calling
• AI receptionist — handle inbound calls from Cambodia across the time-zone gap

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