Cambodia Visa on Arrival and e-Arrival Card for Indian Passport Holders: Fees, CeA Digital Registration, Airport Clearance, and Extension Rules

Quick Summary

• Primary Update: Ordinary Indian passport holders visiting Cambodia for tourism, leisure, or cultural exploration are fully eligible for a 30-day single-entry Visa on Arrival (Type T Tourist Visa) at all international air gateways, including Siem Reap Angkor International Airport (SAI) and Phnom Penh International Airport (PNH), for a statutory fee of USD 30. Alternatively, travelers can secure an official electronic visa in advance via the Ministry of Foreign Affairs portal (evisa.gov.kh) for USD 36.
• Transit Impact: Cambodia has eliminated all physical paper entry forms. Every arriving passenger—regardless of whether they hold an advance e-Visa, a diplomatic passport, or plan to buy a Visa on Arrival—must complete the digital Cambodia e-Arrival (CeA) card within 7 days prior to arrival via arrival.gov.kh or the official mobile application. Arriving at border control without the generated CeA QR code delays entry and requires completing the form on dedicated airport tablet kiosks.
• Traveler Advice: Cash payment at the Visa on Arrival counter must be made exclusively in physical US Dollars (USD). Banknotes must be in pristine condition: crisp, completely uncreased, unsoiled, and free of any tears, pen markings, or stamps. Bringing along one physical passport photograph (4x6 cm) avoids an on-the-spot $2 to $3 cash scanning penalty. In addition, airlines departing India strictly require proof of a confirmed return or onward ticket within 30 days before issuing a boarding pass.

Aviation connectivity between India and Cambodia has reached unprecedented levels. Direct flights linking New Delhi (DEL) to Phnom Penh (PNH), alongside seamless single-connection routes through Bangkok Suvarnabhumi (BKK), Bangkok Don Mueang (DMK), Singapore Changi (SIN), Kuala Lumpur (KUL), and Ho Chi Minh City (SGN), carry thousands of Indian leisure travelers, cultural pilgrims, and business delegates each week to the UNESCO World Heritage monuments of Angkor Wat and the economic centers of Phnom Penh and Sihanoukville.

Cambodia’s Department of Immigration operates a welcoming, streamlined entry regime for Indian nationals. Unlike neighboring Thailand and Malaysia, which offer unilateral visa-free exemption schemes, the Kingdom of Cambodia requires Indian passport holders to obtain a visa. However, the system is designed for maximum efficiency: Indian citizens can obtain a Visa on Arrival (VoA) in minutes at the airport, apply online for an e-Visa beforehand, or submit documents digitally through the integrated national arrival portal.

Understanding the interaction between statutory visa fees, the mandatory Cambodia e-Arrival (CeA) registration, airport layout changes following the launch of the new Siem Reap Angkor International Airport (SAI), and strict banking rules regarding US dollar banknotes is essential for avoiding border delays. This operational manual outlines the exact procedures, statutory fee schedules, airport walkthroughs, overland border precautions, and extension protocols for Indian passport holders.

1. Statutory Framework and Entry Options Comparison

Under the Law on Immigration of the Kingdom of Cambodia and regulations enacted by the Ministry of Interior, foreign nationals entering for tourism are categorized under the Type T (Tourist) visa index, while commercial and professional visitors enter under the Type E (Ordinary / Business) index. Both categories are accessible to Indian passport holders on arrival or via digital pre-application.

Indian travelers have two primary entry pathways for short-term visits: obtaining a physical Visa on Arrival (VoA) upon touchdown or applying in advance for an electronic Visa (e-Visa).

The table below contrasts the legal parameters, processing costs, validity windows, and operational logistics of each entry mechanism:

2. The Mandatory Cambodia e-Arrival (CeA) System

The General Department of Immigration has modernized the nation's port-of-entry infrastructure by replacing all three traditional paper slips—the paper Arrival/Departure Card, the paper Customs Declaration Form, and the physical Health Declaration slip—with a unified digital portal known as the Cambodia e-Arrival (CeA) system.

Key Operating Rules for the CeA Form

1. Submission Window: The digital CeA card can only be submitted within 7 days before your scheduled entry into Cambodia. Submissions made earlier than 7 days will be rejected by the portal's date validator.
2. Platform Cost: The CeA system is 100% free of charge. If a website requests a processing fee, credit card number, or administrative charge for submitting an arrival declaration, you are on an unauthorized third-party intermediary site. Use only the official government domain (arrival.gov.kh) or download the official app titled "Cambodia e-Arrival" developed by the General Department of Immigration.
3. QR Code Verification: Upon completing the electronic declaration, the portal produces a unique QR code containing an encrypted summary of your immigration, health, and customs declarations. Arriving passengers must capture a screenshot of this QR code on their smartphone or print a physical copy.
4. Offline Capability: The mobile app allows users to fill out information while offline and submit once connected to Wi-Fi. However, completing the form prior to boarding your departing flight from India or transit hub (Bangkok, Singapore, or Kuala Lumpur) guarantees that your QR code is cached on your device before entering areas with limited terminal roaming.
5. Integrated e-Visa Application Option: The CeA mobile application also provides an optional built-in feature allowing travelers to purchase an electronic visa directly through the app. Alternatively, travelers can simply select "Visa on Arrival" inside the CeA form and pay the USD 30 fee in cash upon landing.

3. Physical Cash Currency Rules: The "Crisp USD Notes" Invariant

The financial ecosystem of Cambodia is uniquely dollarized. The United States Dollar (USD) functions as legal tender alongside the Cambodian Riel (KHR), with fixed market exchange conventions (typically $1 USD = 4,000 to 4,100 KHR). At all international airports and land border checkpoints, Visa on Arrival fees are quoted, assessed, and collected in US Dollars.

However, Cambodian immigration authorities and commercial banking clearinghouses enforce an inflexible standard regarding the physical quality of foreign currency:

Warning · Operational Advisory

Strict US Dollar Banknote Scrutiny
Cashiers at Cambodian Visa on Arrival counters will instantly reject US dollar bills that exhibit any of the following defects:

• Any tear, micro-rip, or frayed edge (even a 1 mm edge tear).
• Any pen markings, bank teller ink stamps, handwritten notes, or pencil graphite.
• Heavy creases, deep center folds, or faded text/portraits.
• Water damage, pinholes from paperclips, or severe discoloration.
• Banknotes printed prior to the 2013 redesign series.

Tactical Currency Instructions for Indian Passport Holders

• Acquire Clean Bills in India: When buying foreign exchange at authorized forex dealers, bank branches, or airport money changers in India, explicitly demand "mint-condition, uncirculated, uncreased, series-2013 or newer US dollar notes without any bank stamps." Inspect both sides of every single banknote before accepting it.
• Carry Exact Denominations: Carry exact change for your visa transaction: three clean $10 bills, or one $20 bill and one $10 bill. Avoid handing over a $50 or $100 bill for a $30 visa fee, as cashier desks frequently return your change in Cambodian Riel at unfavorable internal exchange rates or hand back older, slightly worn USD bills that local shops in Siem Reap or Phnom Penh will decline to accept.
• Photograph Backup: Carry at least one spare $5 or $10 clean bill in case immigration cashiers determine that you must pay the $2 photo scanning fee.
• Credit Card Terminal Unreliability: While electronic payment terminals (POS) accepting Visa and Mastercard have been piloted at selected counters in Siem Reap (SAI) and Phnom Penh (PNH), network timeouts, foreign bank authorization blocks, and additional 3% merchant processing surcharges make relying exclusively on credit cards risky. Always carry the requisite USD cash in your carry-on luggage.

4. International Gateway Terminal Walkthroughs

Cambodia operates two primary international air hubs servicing passenger routes from India: the modern Siem Reap Angkor International Airport (SAI) and the capital hub Phnom Penh International Airport (PNH). A third major gateway, Techo International Airport (KTI), is designed to replace PNH as the capital’s primary long-haul hub.

Gateway A: Siem Reap Angkor International Airport (SAI)

Commissioned in late 2023 to protect the fragile ancient foundations of the Angkor temple complex from low-altitude jet engine vibrations, SAI is located approximately 45 kilometers east of Siem Reap city center.

[Aircraft Gate / Aerobridge]
                                                                  |
         v
[Main Concourse Corridor] ----> Walk toward central Immigration Hall
                                                                  |
                +------------------------+------------------------+
                |                                                 |
                v                                                 v
     [Holders of e-Visa]                              [Need Visa on Arrival]
                |                                                 |
                |                                 [VoA Cashier Service Counter]
                |                                 - Submit: Passport + Photo
                |                                 - Pay: $30 USD crisp cash
                |                                 - Wait 5-10 min for name call
                |                                 - Collect passport with sticker
                |                                                 |
                +------------------------+------------------------+
                                                                  |
                                         v
                         [Border Control Immigration Lanes]
                         - Present passport with visa
                         - Scan Cambodia e-Arrival (CeA) QR code
                         - Biometric capture: 10 fingers + facial photograph
                         - Officer stamps 30-day entry permit
                                                                  |
                                         v
                             [Baggage Claim Hall]
                                                                  |
                                         v
                      [Customs Screening & Inspection Desk]
                      - Scan CeA QR Code at customs terminal
                      - Luggage X-ray screening
                                                                  |
                                         v
                               [Public Arrival Hall]
            - Airport Express Bus Counter ($8 USD to Siem Reap CDF)
            - Official Metered Taxi Desk ($35 USD flat sedan / $40 van)
            - Local SIM card booths (Smart / Cellcard: $6-$10 USD)

Step-by-Step Arrival Procedure at SAI

1. Concourse to Immigration Hall: Follow directional signage toward International Arrivals. Free terminal Wi-Fi (SAI Airport Free WiFi) is available without SMS authentication if you need to access your stored CeA QR code or hotel booking voucher.
2. Visa on Arrival Desk (Left Wing): If you do not possess an advance e-Visa, approach the wide Visa on Arrival counter situated immediately before the immigration inspection lines. Hand your original passport, one physical photo, and your completed arrival declaration to the intake officer.
3. Payment and Vignette Affixation: Move along the counter to the cashier window. Hand over USD 30 in pristine cash (or $32 if you did not bring a photograph). An overhead monitor displays passenger names and nationality flags when passports are processed. Within 5 to 10 minutes, an officer will call your name and return your passport with an official full-page green/blue Visa on Arrival sticker affixed.
4. Primary Border Control: Join the standard foreign passenger inspection queues. Hand your passport (open to the visa page) and present your mobile device displaying the CeA QR code. The officer scans the QR code, verifies your flight data, captures a high-resolution facial portrait, and directs you to place your fingers on the optical biometric scanner (four right fingers, right thumb, four left fingers, left thumb). The officer stamps your passport with a rectangular entry cachet indicating your permitted 30-day stay date.
5. Luggage Retrieval and Customs Gate: Proceed downstairs to the baggage claim carousels. After retrieving your checked luggage, proceed to the customs checkpoint. Show your CeA QR code to the customs officer, who scans it against their handheld terminal. Place all bags through the X-ray scanner before stepping into the arrivals lobby.

Transport from SAI to Siem Reap Town

Because SAI is situated 45 kilometers outside the city center, transit logistics require advance planning:

• Official Airport Express Bus: Operates scheduled hourly departures connecting SAI with the downtown terminal at CDF Angkor Duty Free Store in Siem Reap city. One-way fare is USD 8, with a journey time of 60 to 75 minutes.
• Official Airport Taxi / Minivan: Fixed-rate vouchers are purchased at the official transport desk inside the terminal lobby. Standard sedans (up to 3 passengers) cost USD 35, while 7-seater minivans cost USD 40. Vehicles travel via the dedicated 24.5-kilometer airport expressway.
• Pre-Arranged Hotel Transfers: Most 4-star and 5-star hotels in Siem Reap arrange private airport pick-ups; ensure you supply your driver with your exact flight number, as drivers park in the designated ground transport holding zone outside the passenger terminal.

Gateway B: Phnom Penh International Airport (PNH)

Phnom Penh International Airport handles non-stop services from New Delhi and major regional hubs across Asia. The terminal is compact, making transfers and immigration clearance straightforward.

• Layout: Arriving passengers step off aerobridges directly onto the second-floor arrival mezzanine and proceed down the central escalators to the ground-floor immigration hall.
• VoA Desk: The counter is located directly facing the foot of the arrival escalators. The operational sequence mirrors SAI: submit documents at Counter 1, pay USD 30 cash at Counter 2, and collect your stamped passport at Counter 3.
• Transit to Downtown Phnom Penh: Located just 10 kilometers west of the central riverfront and Daun Penh district, PNH offers diverse transit options:
  • Grab App / PassApp: Available immediately outside the terminal gates; a 3-wheeler auto-rickshaw (TukTuk) to the city center costs between USD 4 and USD 6 (16,000 to 25,000 KHR).
  • Airport Taxi: Available at the official kiosk for a flat fee of USD 12 to USD 15.
  • City Bus (Line 03): Stops directly outside the airport gates on Russian Federation Boulevard, connecting to the central railway station and night market for 1,500 KHR (~USD 0.38).

5. Overland Land Border Checkpoints and Scam Avoidance

Many Indian travelers explore Southeast Asia via overland routes, combining Thailand, Cambodia, and Vietnam on an extended itinerary. Cambodia permits Visa on Arrival issuance at major land border checkpoints, but travelers must remain alert to regional tout operations.

Key Overland Border Checkpoints

1. Poipet Border Checkpoint (Banteay Meanchey Province): Connects Aranyaprathet (Sa Kaeo, Thailand) with Poipet, Cambodia. This is the primary overland artery between Bangkok and Siem Reap.
2. Bavet Border Checkpoint (Svay Rieng Province): Connects Moc Bai (Tay Ninh, Vietnam) with Bavet, Cambodia. The standard overland bus corridor between Ho Chi Minh City and Phnom Penh.
3. Cham Yeam Border Checkpoint (Koh Kong Province): Connects Hat Lek (Trat, Thailand) with Koh Kong, Cambodia. Popular with coastal travelers heading to Sihanoukville or Koh Rong.

[Aranyaprathet, Thai Side]
  |
  |---> SCAM TRAP 1: Roadside "Government Visa Offices" & Travel Agency Touts
  |     Touts claim: "You must buy Cambodian visa before the border!"
  |     Demanded fee: 1,500 - 2,000 THB (~$45-$60 USD).
  |     DEFENSE: IGNORE completely. Keep walking straight to Thai Immigration.
  |
  v
[Official Thai Border Immigration Control]
  - Stamp exit out of Thailand in your Indian passport.
  - Walk through the covered pedestrian walkway across Friendship Bridge.
  |
  |---> SCAM TRAP 2: Bogus "Medical Quarantine / Fever Screening" Desks
  |     Unofficial personnel in lab coats demand 100-200 THB for a health slip.
  |     DEFENSE: Walk past them. Cambodia requires NO paper health checks.
  |
  v
[Official Cambodian Immigration Office - Right-Hand Side of Road]
  - Enter the air-conditioned government building.
  - Submit: Passport, CeA QR code, physical photo.
  - Pay statutory fee: USD 30 in crisp cash.
  |
  |---> SCAM TRAP 3: Informal "100 THB / $5 Processing Tip" Request
  |     Official may ask: "100 Baht service fee, please."
  |     DEFENSE: Politely smile and state: "I only have $30 USD cash."
  |     Point to the official government fee sign showing $30.
  |
  v
[Passport Stamped] -> Walk to Border Passport Control -> Enter Cambodia.

Essential Overland Rules

• Hold Physical US Dollars: Never attempt to pay for a Cambodian Visa on Arrival at land borders using Thai Baht (THB) or Vietnamese Dong (VND). Immigration booths at land crossings convert foreign currencies at predatory internal exchange rates, charging up to 1,500 THB (approximately $45 USD) for a $30 visa. Always bring crisp US dollar banknotes from Bangkok or Ho Chi Minh City.
• Pre-Arrival CeA Compliance: Even at land borders, foreign visitors must present their completed Cambodia e-Arrival QR code. Wi-Fi connections in border zones are notoriously unstable; ensure you complete the declaration online 24 to 48 hours prior to reaching the border post.
• Advance e-Visa Utility at Land Ports: While the physical VoA is available at Poipet, Bavet, and Cham Yeam, securing an official e-Visa online beforehand allows you to bypass the visa cashier counter completely. You can proceed directly to the border control entry queue, significantly reducing exposure to border touts.

6. Visa Extension Protocols and Overstay Penalties

Travelers wishing to extend their stay in Cambodia beyond the initial 30 calendar days granted by a Type T Tourist Visa must comply with strict statutory extension regulations administered by the General Department of Immigration.

Extension Rules for Tourist Visas (Type T)

1. One-Time Extension Limit: A Type T Tourist Visa (whether obtained on arrival or online as an e-Visa) can only be extended ONCE for an additional 30 calendar days.
2. Maximum Permitted Duration: The total maximum continuous stay on a tourist status cannot exceed 60 days from your original entry date. Once the 30-day extension expires, you cannot renew the visa again inside Cambodia. You must exit the country.
3. Transition to Business Status: You cannot convert a Type T Tourist Visa into an employment, retirement, student, or business visa inside Cambodia. If you anticipate working or staying long-term, you must enter the country on a Type E (Ordinary) visa on arrival ($35 USD) rather than a Type T visa.

Where and How to Apply for an Extension

• Official Immigration Headquarters: The General Department of Immigration (GDI) operates its central visa extension complex directly opposite Phnom Penh International Airport on Russian Federation Boulevard (102nd Street, Phnom Penh).
• Processing Time: Direct applications submitted at the GDI office require 5 to 7 business days, during which the department retains your physical passport.
• Statutory Fees vs Agency Processing: The official government extension fee is approximately USD 30 to USD 50. Most foreign tourists utilize licensed travel agencies or visa service offices in Phnom Penh or Siem Reap. These agencies handle document drop-off and collection for an administrative fee of $15 to $25 USD, sparing travelers multiple trips to the immigration headquarters.
• Application Window: Submit your extension application at least 7 to 10 days before your initial 30-day stay expires to account for weekends and public holidays.

Overstay Penalties and Legal Consequences

Days Overstayed           Statutory Penalty / Legal Consequence

Day 1 to Day 30           USD 10 per day fine, payable in cash at border exit.
                          Immigration stamp indicates fine paid.

Day 31 and Beyond         USD 10 per day fine continues to accumulate.
                          Mandatory appearance before General Department of
                          Immigration; risk of formal detention.

Prolonged Overstay        Formal deportation order issued at passenger expense.
(> 60-90 Days)            Immediate 3-year to 5-year blacklist ban entered into
                          national border control database.

Caution · Mandatory Compliance

Overstay Enforcement at Border Checkpoints
Do not attempt to evade an overstay fine. Border control systems automatically compute overstay durations down to the exact day. If you have overstayed by 3 days, you must pay $30 USD in cash to the border inspector before being permitted to clear exit control. Refusal or inability to pay leads to detention at the airport police facility.

7. Mandatory Documentary Checklist for Indian Citizens

Before checking in for your flight at New Delhi, Mumbai, Bengaluru, Chennai, or Kolkata, ensure that you carry every item on this operational checklist:

• Original Indian Passport: Must carry a minimum of six months residual validity from your planned date of entry into Cambodia and contain at least two blank visa pages for the full-page sticker and border entry/exit stamps.
• Physical US Dollar Banknotes: Exactly USD 30 (or USD 32 if without photo) per person for the Visa on Arrival, carried in pristine, crisp, uncreased, unsoiled, series-2013 or newer bills.
• Physical Passport Photographs: Minimum of one color photograph (4x6 cm or standard 2x2 inch Indian passport size) with a pure white background, taken within the last six months.
• Cambodia e-Arrival (CeA) QR Code: Generated within 7 days of departure via arrival.gov.kh or the mobile app, saved offline as an image file on your smartphone, and preferably backed up with a printed paper copy.
• Confirmed Onward / Return Flight Ticket: An e-ticket showing a confirmed flight booking leaving Cambodia within 30 days. Airlines in India enforce this rule during check-in and will deny boarding without it.
• Proof of Accommodation: Printed hotel booking voucher (or confirmation email on your smartphone) covering your initial stay in Siem Reap or Phnom Penh, detailing the hotel name, full physical address, and local contact phone number.
• Proof of Adequate Funds: While rarely requested from families or business travelers, immigration officers reserve the legal right to inspect financial means. Carry at least USD 500 to USD 1,000 in liquid cash, an international credit card with an available balance, or recent digital bank statements on your mobile device.
• Two Printed Copies of e-Visa (If Applicable): If you opted for an electronic visa via evisa.gov.kh instead of a Visa on Arrival, carry two physical paper printouts: one will be collected by border control upon arrival, and the second must be presented upon departure.

8. Customs Declarations, Currency Controls, and Drone Prohibitions

Entering Cambodia involves biosecurity, currency, and property import regulations administered by the General Department of Customs and Excise.

Duty-Free Allowances

Adult international passengers (aged 18 and older) are permitted the following duty-free imports:

• Tobacco Products: Up to 200 cigarettes, or 50 cigars, or 250 grams of loose pipe tobacco.
• Alcoholic Beverages: Up to 2 liters of wine or 1.5 liters of spirits.
• Perfume: Up to 350 ml of perfume or eau de cologne for personal use.

Currency Import Restrictions

There is no ceiling on the amount of foreign currency or traveler's cheques that can be brought into Cambodia. However, if you are carrying physical cash, bullion, or negotiable instruments exceeding an aggregated value of USD 10,000 (or foreign equivalent), you are legally obligated to declare the sum within the customs section of your Cambodia e-Arrival declaration. Failure to declare sums exceeding $10,000 can result in financial penalties and confiscation under anti-money laundering statutes.

Drone Import and Flying Restrictions

Cambodia enforces rigorous restrictions regarding civilian unmanned aerial vehicles (drones):

• Angkor Archaeological Park Ban: Flying a drone anywhere over the Angkor Archaeological Park (including Angkor Wat, Bayon, Ta Prohm, and surrounding reserves) is strictly illegal without written authorization from the APSARA National Authority and the State Secretariat of Civil Aviation. Drones flown without authorization are immediately jammed, confiscated by heritage police, and operators are subject to heavy fines and detention.
• Phnom Penh Urban Ban: Operating drones in Phnom Penh, particularly in areas near the Royal Palace, government ministries, or military bases, is prohibited without municipal police permits.
• Airport Customs Scrutiny: Customs officers at SAI and PNH who detect a drone inside passenger luggage during X-ray screening may require you to register the serial number and execute a written pledge not to fly the device in restricted cultural zones.

9. Frequently Asked Questions (FAQ)

Can Indian passport holders get a Visa on Arrival at the new Siem Reap Angkor Airport (SAI)?

Yes. Siem Reap Angkor International Airport (SAI) operates a fully staffed Visa on Arrival facility in the international arrivals hall. The fee is USD 30 cash, and the standard turnaround time is 5 to 15 minutes. Indian passport holders do not need any pre-approval letter to use this facility.

Is the Cambodia e-Arrival card mandatory if I already hold an approved e-Visa?

Yes. The Cambodia e-Arrival (CeA) registration is a mandatory border declaration required of every arriving passenger, regardless of whether you hold an e-Visa, plan to obtain a Visa on Arrival, or hold diplomatic status. The CeA replaces the old physical immigration and customs paper slips and must be submitted within 7 days prior to arrival.

Can I pay the Visa on Arrival fee with an Indian debit or credit card?

Relying on cards is not recommended. While card processing terminals exist at certain desks, network connectivity failures, foreign bank transaction declines, and additional 3% merchant processing surcharges frequently disrupt payments. You should carry USD 30 in crisp, clean, series-2013 or newer US dollar banknotes in your carry-on luggage.

Why do Cambodian immigration cashiers reject certain US dollar bills?

Cambodian commercial banks and the National Bank of Cambodia enforce strict quality controls on foreign paper currency. Banks will not accept foreign banknotes that have tears, folds, frayed edges, ink marks, teller stamps, or water damage. Because immigration desks must deposit collected fees into national treasury accounts, officers immediately reject any note that shows visible wear or markings.

Can I extend my Cambodia tourist visa beyond 60 days?

No. A Type T Tourist Visa (whether obtained on arrival or online) allows an initial stay of 30 days and can only be extended once for an additional 30 days, creating an absolute limit of 60 continuous days. To stay longer, you must exit Cambodia and return on a new visa, or enter the country initially on a Type E (Ordinary) visa.

Do children and infants require a separate visa and CeA card?

Yes. Every foreign traveler, regardless of age, must hold their own individual passport, obtain a distinct visa (costing the standard $30 USD), and have a completed Cambodia e-Arrival declaration submitted. Parents or legal guardians can submit the CeA declaration on behalf of minors using the "Family Group" feature within the official CeA portal or app.

What happens if I transit through Bangkok, Kuala Lumpur, or Singapore en route to Cambodia?

If you are booked on a single, continuous through-ticket (e.g., IndiGo, Singapore Airlines, Malaysia Airlines, Thai Airways), your checked baggage will be tagged through to Cambodia, and you do not clear immigration at the transit hub. However, if you book two separate tickets on self-transfer budget airlines (such as flying AirAsia into Bangkok Don Mueang and then booking a separate flight to Siem Reap), you must clear immigration in Thailand or Malaysia. Check the visa rules for your transit country (Thailand offers 60-day visa-free entry, and Malaysia offers 30-day visa-free entry for Indian citizens).