Paddle wheel aerators classification retained under HSN 8479 residual heading; concessional GST applied via rate notification.

Paddle wheel aerators used exclusively in aquaculture are functionally classifiable under HSN 8479 (residual heading 84798999) because their mechanical water agitation and oxygen transfer function aligns with machines not elsewhere specified in Chapter 84; consequently they are not covered by HSN 8436 which targets terrestrial agricultural machinery. Notification No. 9/2025-Central Tax (Rate) grants a concessional 5% GST treatment for aquaculture aerators by rate rationalisation without altering HSN classifications, so existing codes like 84798999 receive the rate benefit while parts exclusively for the aerator follow the principal machine classification (and remain at the corresponding rate where 8436 is inapplicable).

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Issues: (i) Whether Paddle Wheel Aerators used exclusively in aquaculture are classifiable under HSN 8436 80 90; (ii) What is the applicable CGST rate on such Paddle Wheel Aerators in view of GST Council recommendations and Notification No. 9/2025; (iii) Whether parts exclusively used in Paddle Wheel Aerators are classifiable under HSN 8436 99 90 and attract 5% GST.

Issue (i): Whether Paddle Wheel Aerators used exclusively in aquaculture are classifiable under HSN 8436 80 90.

Analysis: The Authority examined the product description, function, models and components, prior trade classification under HSN 8479 89 99, relevant notifications (Notification No. 1/2017 and Notification No. 9/2025), and submissions including precedents and policy releases. It compared the scope and explanatory reach of Heading 8436 with the residual Heading 8479 and assessed whether paddle wheel aerators fall within the specific descriptive ambit of 8436 or remain machines having individual functions not specified elsewhere in Chapter 84. The Authority noted the Notification No. 9/2025 master schedule and prior classification practice and concluded that the machine fits the residual description in Heading 8479 rather than a specific subheading of 8436.

Conclusion: The Paddle Wheel Aerator is not classifiable under HSN 8436 80 90; it is classifiable under HSN 8479 8999.

Issue (ii): What is the applicable CGST rate on Paddle Wheel Aerators in light of GST Council recommendations and Notification No. 9/2025?

Analysis: The Authority considered the GST Council's rate rationalization, the PIB/departmental communications, and the entries in Notification No. 9/2025. It evaluated whether the 5% concessional rate for "aerators" necessarily effected reclassification to 8436 or applied functionally to existing headings. Having held that the correct tariff heading is 8479 8999, the Authority determined the applicable rate based on the schedule entries linked to that heading in the governing notification.

Conclusion: The applicable CGST rate on the Paddle Wheel Aerator (HSN 8479 8999) is 18%.

Issue (iii): Whether parts exclusively used in Paddle Wheel Aerators are classifiable under HSN 8436 99 90 and attract 5% GST.

Analysis: The Authority applied the rule that parts are generally classified with the principal machine only if the principal machine's classification so warrants. Since the complete aerator was held to be classifiable under HSN 8479, the parts could not be reclassified under HSN 8436 99 90 merely on exclusivity; parts classification must follow the principal machine heading and the relevant tariff entries in the notification.

Conclusion: The parts are not classifiable under HSN 8436 99 90; the Authority assigns HSN 8479 9090 for the parts and they attract the rate applicable to that heading (as held by the Authority).

Final Conclusion: The Advance Ruling answers the applicant's questions by fixing the tariff classification of the complete Paddle Wheel Aerator and its parts under Chapter 84 residual headings (8479 8999 for the machine and 8479 9090 for parts) and by applying the corresponding GST rates under the controlling notification, thereby denying reclassification into Chapter 8436 and the concessional 5% rate sought by the applicant.

Ratio Decidendi: A machine is classifiable under the specific HSN heading whose descriptive scope it satisfies; parts exclusively used with a machine are to be classified with that machine only if the principal machine falls within that heading; rate concessions directed at a function or sector do not automatically mandate reclassification of goods into a different HSN chapter absent explicit tariff entry to that effect.

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