ORDER MRS. CHITRA VENKATARAMAN, J. - In W.P. Nos. 3226, 3227 and 3228 of 2008, the petitioner seeks a writ of certiorari to quash the order dated December 26, 2007 passed by the first respondent wherein the first respondent herein fixed as benchmark the base level production and sales of the assessment year 1995-96. The petitioner herein set up a unit at Sriperumbudur by way of expansion of its industry. In terms of G.O.Ms. No. 500, Industries (MIG II) Department dated May 14, 1990, the petitioner sought for interest-free sales tax for the expanded unit. The third respondent accordingly granted the eligibility certificate on deferral of sales tax on March 30, 1995 for a period of five years from December 1, 1994 to November 30, 1999 repayable between December 1, 1999 and November 30, 2004. It is stated that the commercial production with reference to the expanded unit commenced in December, 1994. Having regard to the incremental investment of Rs. 281.95 lakhs in the unit, the expanded unit of the petitioner also went in for additional deferral benefit for nine years. In the meantime, the petitioner went in for further expansion by setting up a unit in Vadanavendal Village, Cheyyar Taluk. Being located in the backward area, the petitioner once again went in for a nine year deferral of sales tax from November 1, 1995 onwards. The petitioner was granted the eligibility certificate on September 2, 1996 for interest-free sales tax benefit for a period of nine years. The petitioner - unit commenced commercial production on November 3, 1995. Thus the nine year deferral was for the period from November 1, 1995 to October 31, 2004 repayable from November 1, 2004 to October 31, 2013. As regards the deferral of tax, paragraph 5.3 of the eligibility certificate prescribed the condition that the petitioner has to maintain a benchmark of production, and base sales volume of Axle Housing relating to the assessment year 1994-95. The eligibility certificate prescribed 1994-95 volume of production and sales as a benchmark, viz., 39435 Nos. of Axle Housing and Rs. 3,145.21 lakhs sales turnover and till the unit crossed this, the petitioner had continue to pay the tax as before and the deferral only on the incremental volume of production/sales that the petitioner would be entitled to the deferral of sales tax. of Axle Housing and Rs. 3,145.21 lakhs sales turnover and till the unit crossed this, the petitioner had continue to pay the tax as before and the deferral only on the incremental volume of production/sales that the petitioner would be entitled to the deferral of sales tax. In terms of the eligibility certificate thus granted, the petitioner executed an agreement with the second respondent - Department on October 23, 1996, which also fixed the benchmark of the assessment year 1994-95 in terms of the eligibility certificate. The respondents do not dispute the fact that even though the eligibility certificate was issued on September 2, 1996, as the commercial production of the unit commenced on November 3, 1995, the eligibility certificate was granted for a period of nine years starting from November 1, 1995 to October 31, 2004 keeping the benchmark figures of the assessment year 1994-95 for compliance. The Assistant Commissioner, Commercial Taxes, the second respondent herein, issued a notice dated October 3, 2002, taking the view that as per G.O.Ms. Mo. 119 dated April 13, 1994 and the conditions in the eligibility certificate, the petitioner is eligible for deferral of sales tax only on the increased production and sales, the benchmark figure to be taken as the highest of the production/sales is with reference to any one of the three years preceding the year in which the eligibility certificate was granted and till reaching this figure, the assessee would continue to pay tax and any liability in excess of the above alone would be eligible for deferral. So far, on this line of reasoning, there is no grievance between the petitioner and the Revenue. However, the notice went further to hold that since the eligibility certificate was issued only in September, 1996 and the sanction order was made in October, 1996, the benchmark during the last three years would have to be taken from 1993-94 to 1995-96. Hence, the benchmark would be one relating to the assessment year 1995-96 as against the benchmark fixed relating to that of the assessment year 1994-95. Consequently, the second respondent held that the petitioner had availed of excess deferral and hence called upon the petitioner to pay the tax for the three assessment years 1996-97, 1997-98 and 1998-99 at Rs. 1,32,72,475, Rs. 51,10,230 and Rs. 72,32,106, respectively. Consequently, the second respondent held that the petitioner had availed of excess deferral and hence called upon the petitioner to pay the tax for the three assessment years 1996-97, 1997-98 and 1998-99 at Rs. 1,32,72,475, Rs. 51,10,230 and Rs. 72,32,106, respectively. Aggrieved by the view of the second respondent on the benchmark fixed with reference to 1995-96, the present writ petition is filed. The learned counsel appearing for the petitioner referred to G.O.Ms. No. 119 dated April 13, 1994, requiring that the industry would be eligible for sales tax deferral only if the production in the financial year exceeded the base production volume, which was the highest annual production in the three years prior to expansion and that specification of the base production volume and the base sales volume would have to the worked out and incorporated in the eligibility certificates at the time of issue by SIPCOT and District Industries Centres. Having regard to the above specific requirement of entering the base production volume and the base sales volume in the eligibility certificate, it stands to reason that the jurisdiction to bring any amendment on this front lies only with the authority granting the eligibility certificate and it is not open to the assessing authority to change or alter what had been stated in the eligibility certificate. I agree with the said submission of the learned counsel for the petitioner. It is not disputed by the respondents that the eligibility certificate prescribes the assessment year 1994-95 as the benchmark for the petitioner to maintain to avail of the IFST benefit. As already pointed out, the respondents do not dispute the date of commercial production as on from November 1, 1995, even though the eligibility certificate was granted on September 2, 1996, yet, the deferral period was to commence from November 1, 1995 to October 31, 2004. SIPCOT also fixed the details of the production/sales relating to the assessment year 1994-95 for compliance to avail of the deferral on the incremental turnover and production. That being so, it is not open to the Assistant Commissioner to adopt the figures of an assessment year different from that of what had been stated in the eligibility certificate. Going by G.O.Ms. That being so, it is not open to the Assistant Commissioner to adopt the figures of an assessment year different from that of what had been stated in the eligibility certificate. Going by G.O.Ms. No. 119 dated April 13, 1994 requiring the eligibility certificate to carry the base year with reference to which the petitioner has to maintain the production and sales for the purposes of availing of the deferral of sales tax, it goes without saying that the Assistant Commissioner has no jurisdiction to alter this vital requirement, but to have the agreement executed in tune with what had been stated in the eligibility certificate. Consequently the demand made under the impugned order relating to the assessment years 1996-97 to 1998-99 alleging availing of excess deferral has to be set aside as going beyond the jurisdiction of the second respondent. In the circumstances, I have no hesitation in allowing the writ petitions, thereby setting aside the orders passed by the second respondent herein that the second respondent shall go by the base year fixed under the eligibility certificate, viz., the base production volume to base sales volume referable to the assessment year 1994-95 and cannot adopt a different assessment year as the base year for compliance. Consequently, the order of the first respondent dated December 26, 2007 demanding payment of tax for the assessment year 1996-97 to 1998-99 stands quashed. The writ petitions are allowed. No costs. Connected M.P. Nos. 1, 1 and 1 of 2009 are closed.