JUDGMENT M.C. Desai, C.J. - This appeal arises out of an order by Mootham, C.J. dismissing the appellants petition for a writ to quash certain proceedings for recovery of agricultural income tax from him pending in the court of the Collector, Sitapur. 2. We are concerned with the agricultural income-tax assessed for 1360 Fasli under the U. P. Agricultural Income tax Act, No. III of 1949. The assessing officer assessed the appellant under Section 16(4) of the Act to the tax of Rs. 1,000 and odd: the assessment was ex parte. Section 20 of the Act requires that a notice of demand of tax imposed under Section 16 should be served upon him and naturally he did not pay the tax. If he was aggrieved by the assessment, two remedies were open to him, one by an appeal as provided in Section 21, and the other by an application for revision as provided by Section 22. He chose the second remedy and on 6-3-1954 filed an application in revision before the Board of Revenue, but it was dismissed on 29-11-1954. Section 23 provides that "An authority passing any final order under Section 21 or Section 22 shall communicate such order to the assessee." and in compliance with this provision the Board Communicated to the appellant the result of the revision application, but again no notice of demand was sent to him. Section 30 lays down how the tax is payable. Sub-Sec. (1) lays down that "the amount specified in any notice of demand under Section 20 or in any order communicated under Section 23 shall be payable in four instalments." Sub-Sec. (2) lays down that "the first instalment shall be paid within one month of the service of the notice of demand or communication of the order as the case may be" and each subsequent instalment is to be paid within two months of the previous instalment, and sub-Sec. (3) lays down that "if any instalment is not paid in the time allowed under sub-Sec. (2), the assessee shall be in default: Provided that when an assessee has presented an appeal under section 21, the appellate authority, on application, may, direct that the assessee shall be treated as not being in default." 3. The appellant paid no instalment. On 11-2-1956 the assessing officer, treating him as in default., imposed upon him a penalty of Rs. The appellant paid no instalment. On 11-2-1956 the assessing officer, treating him as in default., imposed upon him a penalty of Rs. 150 in exercise of the power conferred by Section 31 and the penalty also was not paid by him. On 13-2-1956 the assessing officer applied to the Collector under R. 28(4) of the Rules framed under the Act for realisation of the tax and the penalty. Section 32 provides that the Collector on the motion of the assessing authority may recover any penalty imposed under Section 31 or when an assessee is in default, the amount assessed as tax as if it were an arrear of land revenue and that no proceedings for the recovery of any sum payable under the Act can be commenced. "after the expiration of one year from the date on which the last instalment fixed under See. 30 falls due or after the expiration of one year from the date on which any appeal relating to such sum has been disposed of." 4. The appellant appeared before the Collector and objected to his being treated as a defaulter and to the realisation oF the tax and the penalty from him, but the Collector rejected his objection on 7-9-1956. Thereupon he filed the petition, giving rise to this appeal,or certiorari to quash the recovery of proceedings pending before the Collector,on two main grounds (1) that he was never in default, inasmuch as no notice of demand was ever served upon him and (2) that the recovery proceedings were barred by time. 5. The learned Chief Justice repelled the first contention on the ground that the appellant admittedly received a copy of the assessment order and there by knew the amount of the tax assesse by the assessment officer and yet did not pay any instalment. With great respect, we do not agree. An assessed is a defaulter only when he does not pay any of the four instalments on the date on which it fals due. If a notice of demand had been served upon the appellant, the first instalment should have been paid within one month of the date of service and he would have been a defaulter if he had not paid it. Since admittedly no notice of demand was served upon him he did not become a defaulter in this manner. If a notice of demand had been served upon the appellant, the first instalment should have been paid within one month of the date of service and he would have been a defaulter if he had not paid it. Since admittedly no notice of demand was served upon him he did not become a defaulter in this manner. The only other manner in which he could be a defaulter was that he did not pay the first instalment within one month of the date of the communication of the order under Section 23 of the U. P. Agricultural Income Tax Act. The only order that could have been communicated to him under Section 23 was the order of the Board of Revision dismissing his application for revision. It was served upon him on 29-11-1954, as conceded by the Counsel for the parties, but the first instalment did not fall due within one month of it for the simple reason that no amount was specified in the order communicated to him. The Board simply rejected the application for revision without stating the amount of the tax assessed upon the appellant and maintained by it. The words "communication of the order" in sub-Sec. (2) of Section 30 means the order referred to in sub-Sec. (1), e.g. the order in which the amount of the tax has been specified. If no amount has been specified in the order communicated, there is no question of any amount being payable in four instalments and of the first instalment being due on any date. Consequently, it could not be contended that the first instalment fell due on 29-12-54 and that the appellant became a defaulter by not paying it. When there was no service of a notice of demand or of any order in which the amount of the tax was specified, there was no date on which the first instalment fell due and the appellant could never be a defaulter. 6. The appellants being aware of the amount of the tax assessed upon him is quite irrelevant his knowledge of the amount does not amount to his liability to pay it and nothing depends upon it. 6. The appellants being aware of the amount of the tax assessed upon him is quite irrelevant his knowledge of the amount does not amount to his liability to pay it and nothing depends upon it. His liability to pay arises from the service of a notice of demand or of an order communicated to him under Section 23 of the Act and specifying the amount of the tax to be paid by him, and not from his knowledge of the assessment order or its amount. Section 30 contains the only provision stating when the amount of the tax is payable; there is nothing in its language to suggest that the amount becomes payable on the date of the knowledge of the assessment order, or on the expiration of a month from it. Passing an assessment order and serving a notice of demand are two different acts required to be performed by the Act and evidently one act cannot be treated as equivalent to, or dispensing with, the other. 7. Since we find that the appellant was not a defaulter, no recovery proceedings could be taken under Section 32 of the Act at all and it is not necessary for us to go into the other question whether they were barred by time or not. 8. Sri S. D. Misra contended that the appellant by not filing a petition for certiorari to quash the order imposing the penalty is now estopped from contending that he is not a defaulter. On account of his being declared to be a defaulter two consequences arose, (1) that the penalty was to be imposed on him, and (2) that the recovery proceedings could be commenced. Both the consequences arose in this case and the appellant submitted to the first consequence (by not challenging the imposition of the penalty) but he was not estopped from challenging the second consequence, as there is no provision of law laying down that if the order of imposition of penalty is not challenged the assessee cannot challenge the finding that he was a defaulter and the recovery proceedings commenced under section 32 of the U.P. Agricultural Income-Tax Act. 9. 9. In the result, we allow this appeal with costs, set aside the judgment of the learned Chief Justice, allow the petition of the appellant and quash the proceedings pending before the Collector for the recovery of the Agricultural Income-Tax and the penalty.