CNG Endorsement in RC

When a vehicle leaves a factory or showroom fitted with a petrol or diesel engine, its Registration Certificate (RC) carries the fuel type that the manufacturer certified at the time of production. Every vehicle’s RC is a legal record of the vehicle’s specifications – including the fuel type – and that record sits permanently with the Regional Transport Office that issued the RC. If you subsequently install a Compressed Natural Gas (CNG) kit in your vehicle to use CNG as a fuel, you are making a modification to the vehicle’s propulsion system. Under the Motor Vehicles Act, 1988 and the Central Motor Vehicles Rules, 1989, any alteration to a vehicle that changes its specifications from those originally certified and recorded on the RC must be notified to the RTO and recorded as an endorsement on the RC before the modified vehicle can legally ply on public roads.

This process of getting the CNG conversion reflected on your RC is commonly referred to as CNG endorsement, CNG endorsement in RC, or CNG kit approval from RTO. Until this endorsement is done and the updated RC is issued, a vehicle running on CNG is technically in violation of Section 52 of the Motor Vehicles Act, 1988, which prohibits alterations to a motor vehicle that are not in accordance with the manufacturer’s specifications without prior approval from the registering authority. Traffic police and enforcement agencies have the authority to detain vehicles found running on un-endorsed CNG kits, and insurance companies can use the absence of RC endorsement as a ground to repudiate claims in the event of an accident.

The CNG endorsement requirement applies equally to retro-fitted CNG kits – meaning kits installed by an aftermarket retrofitter after the vehicle was originally purchased – and, in practice, even to some factory-fitted CNG vehicles where the dealer or owner did not complete the endorsement step at the time of original registration. The scale of vehicles running on un-endorsed CNG kits across Indian cities is significant, largely because the endorsement requirement is not prominently communicated at the point of kit installation. Most CNG kit installers in the aftermarket are authorized to fit the kit but are not responsible for the RTO endorsement step, which has to be initiated separately by the vehicle owner.

The legal basis for CNG retrofitting is rooted in the approvals system managed by the Ministry of Road Transport and Highways. CNG retrofit kits sold in India must carry type approval from the Automotive Research Association of India (ARAI) or the Vehicle Research and Development Establishment (VRDE), which are the testing agencies authorized to certify kits as safe for fitment in specific vehicle models. A kit with valid type approval can legally be fitted to the vehicle models listed in its approval certificate. When you submit your endorsement application to the RTO, the type approval certificate for your specific kit – along with the installation certificate from the retrofitter – is a core document the RTO uses to validate that the modification is permissible under the rules.

In addition to the RC endorsement, vehicles using CNG as fuel may need a periodic hydrostatic testing of the CNG cylinder to confirm the cylinder remains safe for use under pressure. The Central Motor Vehicles Rules specify testing intervals for CNG cylinders, and the cylinder’s test certificate is a document that enforcement agencies and insurance companies may ask for separately from the RC endorsement. The cylinder test and the RC endorsement are two distinct requirements – getting one done does not substitute for the other.

Practically, what Kagzikaam sees most often is vehicle owners who had a CNG kit installed years ago, have been driving on it without any issue so far, and then encounter a problem – at a traffic check, at insurance renewal, or when trying to sell the vehicle – where the missing RC endorsement becomes a blocking issue. At that point, the endorsement process can still be completed, but it now runs alongside resolving the non-compliance record, which adds steps. Getting the endorsement done proactively – ideally within 90 days of kit installation, which is the window most state transport departments prescribe – avoids this compounding entirely.

Vehicles Covered – Two-Wheelers, Four-Wheelers, and Commercial Vehicles

The CNG endorsement requirement covers all categories of motor vehicles fitted with CNG kits – private cars, two-wheelers (though CNG two-wheelers remain less common), goods vehicles, auto-rickshaws, buses, and taxis. For commercial vehicles running on CNG – particularly auto-rickshaws and taxis in cities where CNG is mandated by court orders or pollution control requirements – the RC endorsement is especially critical because commercial vehicle permits are checked more frequently during enforcement drives. In many cities, a commercial vehicle on CNG without RC endorsement can face permit suspension in addition to the standard penalty.

Factory-Fitted CNG vs Retro-Fitted CNG

When a vehicle is sold with a CNG kit pre-installed at the factory – as several car manufacturers now offer as a standard variant – the manufacturer’s ARAI type approval covers the entire vehicle-kit combination, and the dealer is responsible for ensuring the RC issued at the time of registration already reflects CNG as the fuel type. If you purchased a factory-fitted CNG vehicle and your RC still shows only petrol or diesel, the omission is the dealer’s, and the endorsement can be added at the RTO without the standard alteration process, since the manufacturer’s own type approval covers the modification. For retro-fitted kits installed after purchase, the kit installer’s type approval certificate is what the RTO relies on.

What the RC Endorsement Actually Changes

Once the CNG endorsement is processed, the fuel type field on your RC is updated to reflect CNG + petrol (for bi-fuel vehicles, which describes most retro-fitted CNG cars that retain the original petrol system) or CNG only where the vehicle runs exclusively on CNG. The updated RC is issued as a fresh Smart Card with the amended details. The vehicle’s engine number, chassis number, and all other specifications remain unchanged – only the fuel type entry is updated to reflect the CNG addition.

CNG Endorsement and Vehicle Insurance

Most vehicle insurance policies require disclosure of any CNG kit fitment at the time of policy issuance or renewal. An un-endorsed CNG kit that has not been disclosed to the insurer, and which does not appear on the RC, can be treated as a material non-disclosure – which gives the insurer grounds to deny a claim if the vehicle meets with an accident. Once the RC endorsement is done and the updated RC reflects CNG, informing your insurance company and getting the policy endorsement updated accordingly is the next step to ensure your coverage is complete and not at risk of claim rejection on these grounds.

Timeline From Kit Installation to RC Update

Most state transport departments prescribe that the application for CNG endorsement be submitted within 30 to 90 days of the kit installation date. The RTO inspection is typically completed within a few days of application submission if documents are in order. The updated Smart Card RC is then dispatched by post, usually within 15 to 30 working days after inspection clearance, depending on the RTO’s dispatch queue. Delays are most commonly caused by incomplete documents at the first submission or by the RTO flagging a mismatch between the vehicle’s chassis number and the kit installation certificate.

Our CNG Endorsement Services

How the CNG Endorsement Process Works

Documents and Forms Required

CNG Endorsement Fee Structure

CNG endorsement fees are set by individual state transport departments. The Central Motor Vehicles Rules provide the enabling framework for registration amendments, while the actual fee amounts and Smart Card charges are prescribed in state-specific rules and are revised periodically by state governments. The table below covers the typical fee components applicable in most states.

Additional Cost Consideration – Insurance Endorsement

After the RC is updated with CNG endorsement, your motor insurance policy also needs to be updated to reflect the CNG fitment. Most insurers charge a small additional premium for the CNG kit as an add-on or as an endorsement to the existing policy. The premium increment is typically modest, but it is a step that should not be skipped since coverage gaps can arise at the time of a claim if the insurer’s records do not match the updated RC.

Rules and Eligibility

The legal framework for CNG kit retrofitting and RC endorsement in India is anchored in the Motor Vehicles Act, 1988 and the Central Motor Vehicles Rules, 1989, with additional circulars and guidelines issued by the Ministry of Road Transport and Highways from time to time.

Section 52 of the Motor Vehicles Act, 1988

Section 52 of the Motor Vehicles Act prohibits any alteration to a motor vehicle that changes the specifications from those in the manufacturer’s certificate of compliance, without the prior approval of the registering authority. Installing a CNG kit in a vehicle that was not originally manufactured with CNG capability is an alteration covered under this section. The requirement to get RTO approval and RC endorsement flows directly from this provision. Penalties under Section 52 for driving with an unendorsed modification include a fine and, for repeated violations, potential suspension of the driving licence.

ARAI / VRDE Type Approval Requirement

Under the Central Motor Vehicles Rules, only CNG kits with valid type approval from ARAI or VRDE may be legally fitted to vehicles in India. The type approval certifies that the kit has been tested and found safe and compatible for fitment in specific vehicle makes, models, and year ranges. An RTO will not process a CNG endorsement application for a kit that does not carry type approval, or where the kit model’s approval does not list the applicant’s vehicle model as a compatible fitment. This is the most common ground for endorsement rejection – kit fitters sometimes install a kit that is approved for a similar but technically different vehicle variant, and the mismatch shows up only when the type approval certificate is reviewed at the RTO.

Authorized Retrofitter Requirement

The CNG kit must be installed by a retrofitter who is authorized by the kit manufacturer and who is recognized by the state transport department or the relevant authority. An installation certificate from an unauthorized fitter – even if the kit itself carries ARAI approval – may not be accepted by the RTO as valid documentary evidence of compliant installation. Most states maintain a list of authorized CNG retrofitters; verify your installer is on this list before getting the kit fitted if you intend to complete the RC endorsement.

CNG Cylinder Safety – Bureau of Indian Standards

CNG cylinders used in vehicles must conform to IS 15935 (for seamless steel cylinders) or other applicable BIS standards, and must carry the BIS mark. Beyond initial compliance, the Central Motor Vehicles Rules require periodic hydrostatic testing of CNG cylinders – typically every three years for cylinders in private vehicles and more frequently for commercial vehicles. A cylinder that has exceeded its test validity period is non-compliant even if the RC endorsement is current, and can be grounds for enforcement action independently of the endorsement status.

Hypothecated Vehicles

For vehicles under a hypothecation agreement with a bank or NBFC, some states require the financier’s written consent before the RTO will process a modification endorsement like a CNG addition. This is because the RC amendment changes the vehicle’s specification as recorded in the financier’s loan records. Even in states where this is not a hard requirement, the financier should be informed of the modification since the vehicle is their security against the loan.

Commercial Vehicles – Fitness Certificate Update

For commercial vehicles – including taxis, auto-rickshaws, and goods vehicles – a CNG endorsement may also require an update to the vehicle’s Fitness Certificate under the Central Motor Vehicles Rules, since the fitness certificate certifies the vehicle’s condition and specifications for road worthiness. An updated fitness certificate that reflects the CNG fitment may be required before the RC endorsement is processed, or may need to be obtained concurrently. Check with your RTO or Kagzikaam for the specific requirement for your vehicle category.

No Time Limit for Late Endorsement, But Penalties Apply

There is no absolute legal cutoff that permanently bars a late endorsement application – you can apply for CNG endorsement even if the kit was installed years ago. However, driving on an unendorsed CNG kit for an extended period means the vehicle has been in violation of Section 52 throughout that period, and enforcement action during that time – such as a traffic challan – will carry the standard penalties. The endorsement, once done, corrects the RC prospectively. It does not retroactively clear any penalties that may have been levied during the period of non-compliance.

Why Choose Kagzikaam

Kagzikaam manages CNG endorsement across cities in India, handling document verification, RTO coordination, and Smart Card tracking end-to-end – keeping you updated on Whatsapp at every step so you never have to make an unplanned RTO visit.

Frequently Asked Questions