Judgment :- Paripoornan, J. The same assessee is the revision-petitioner in both the revisions. The respondent in both the cases is the Revenue. The revisions are filed against the common order passed by the Sales Tax Appellate Tribunal, Thiruvananthapuram dated 18-6-1991 in T.A.Nos. 529 and 671 of 1988. The revisions as also the appeals before the Sales tax Appellate Tribunal relate to the assessment for the year 1986-87. 2. The petitioner is an assessee under the Kerala General Sales Tax Act. It is a dealer in arrack. During the relevant year, it had 12 shops (14 arrack shops and 8 sub-shops). For the relevant year, the assessee conceded total exempted turnover of Rs.39,17,799/- towards the second sale of arrack. The assessing officer found the accounts incorrect and incomplete for six reasons stated in the order of assessment. The important defects highlighted were that the accounts maintained in the sub-shops were not produced for scrutiny, that the vouchers for the expenditure incurred are not forthcoming, that no turnover of soda, soft drinks (Cola) and arishtam were conceded and that when the business place of the dealers at Paramattom, one of the shops, was inspected by the Intelligence wing of the department on 21-10-1986, stock variation and discrepancies were found out. The assessee compounded the offence by paying Rs.7,000/-. It was noticed that the total turnover of arrack was in the sum of Rs.39,17,799/-. The excess stock difference of 608 litres, found out on the surprise inspection on 21-10-1986 worked out to 17% of the book stock for the day; so the Sales tax Officer added for omission and suppression a sum of Rs.6,66,025.83, which represented 17% addition to the turnover returned. There was an addition of 2% on the estimated turnover relating to Soda, Cola and Arishtam, empty bottles for arishtam and caps coming under S.SA of the Act. The total taxable turnover was arrived at Rs.7,65,300/- and the tax liability of Rs.3,29,168/- and a surcharge of Rs.21,945/- was fixed. 3. In appeal, the Appellate Assistant Commissioner reduced the estimate and held that a lump sum addition of Rs.1,50,000/- will be more just and reasonable. Similarly, the addition of Rs.91,677/- made for cola, soda, arishtam was reduced to Rs.75,000/- the assessee appealed before the Sales tax Appellate Tribunal and pleaded for more reduction. 3. In appeal, the Appellate Assistant Commissioner reduced the estimate and held that a lump sum addition of Rs.1,50,000/- will be more just and reasonable. Similarly, the addition of Rs.91,677/- made for cola, soda, arishtam was reduced to Rs.75,000/- the assessee appealed before the Sales tax Appellate Tribunal and pleaded for more reduction. The Revenue filed an appeal before the Sales tax Appellate Tribunal and objected to the reduction in the turnover made by the Appellate Assistant Commissioner. Both the appeals were heard together and a common order was passed by the Sales tax Appellate Tribunal dated 18-6-1991. The Appellate Tribunal allowed the appeal filed by the Revenue and dismissed the appeal filed by the assessee and the modification in the quantum of addition sustained by the first appellate authority was set aside. The Tribunal virtually restored the assessment order. The assessee objects to the common order passed by the Appellate Tribunal in T.A.Nos. 529 and 671 of 1988. 4. We heard counsel for the revision petitioner Mr.Premjit Nagendran as also counsel for the respondent/Revenue-senior Government Pleader Mr. V.C. James. Counsel for the revision-petitioner raised two fold arguments. Firstly it was argued that even conceding that accounts produced are not acceptable and a best judgment assessment is warranted, the assessment should be based on material. It was argued that on the basis of the stock difference for one day in one shop, which worked out to 17% of the book stock for the day, the assessing authority was in error in adopting the same percentage even for that shop for the whole year; what is more there is no presumption that there was suppression or stock difference in the said shops much less at the same rate. Based on the excess stock difference of 17% of the book stock for one day, it was not permissible for the assessing authority to estimate the turnover for the whole year for all the shops at the same percentage. Secondly, it was argued that the assessment is based on no material and the first appellate authority found that a lump sum addition of Rs. 1,50,000/- will be just and reasonable for the various reasons stated in its order dated 12-5-1988. Secondly, it was argued that the assessment is based on no material and the first appellate authority found that a lump sum addition of Rs. 1,50,000/- will be just and reasonable for the various reasons stated in its order dated 12-5-1988. Before setting aside the said order, the Sales tax Appellate Tribunal had a duty to demonstrate that the order of the Appellate Assistant Commissioner is wrong and that it requires to be set aside and the assessment should be based on a different basis. It has not been so done in the instant case. So, the order of the Appellate Tribunal is erroneous in law. 5. On the other hand, counsel for the Revenue submitted that admittedly on a surprise inspection of the business premises of the assessee at Paramattom on 21-10-1986 stock variation and other discrepancies were found out. The assessee did not produce the accounts of the various shops for scrutiny. The turnover on soda, soft drinks, and arishtam were not disclosed. These and other defects entailed rejection of accounts and warranted a best judgment assessment. The best judgment assessment made by the assessing authority is based on material. The material being the excess stock difference found on the inspection on 21-10-1986 which worked out to 17% of the book stocker day. The assessing authority was justified in adopting the same percentage for the whole year, for the Paramattom shop and for other shops, since it was probable that the assessee would have excess stock on other days and also in other shops. The Appellate Assistant Commissioner fixed the addition on a lump sum basis at Rs.1,50,000/- arbitrarily. The Sales tax Appellate Tribunal having found that the books of accounts are not acceptable was justified in restoring the order passed by the assessing authority, since the interference made by the Appellate Assistant Commissioner was unauthorised and unwarranted. 6. Having heard the rival pleas placed before us, we are of the view that the pleas urged by the assessees counsel should prevail. It is true that the assessing authority has pointed out six defects for rejecting the books of accounts. There can be no doubt and we concur with the Appellate Tribunal in holding that the books of accounts of the assessee are not acceptable. In other words, the returns filed by the assessee cannot be accepted to fix the taxable turnover. It is true that the assessing authority has pointed out six defects for rejecting the books of accounts. There can be no doubt and we concur with the Appellate Tribunal in holding that the books of accounts of the assessee are not acceptable. In other words, the returns filed by the assessee cannot be accepted to fix the taxable turnover. A best judgment assessment is called for in this case. To this extent, the Revenue should succeed. 7. Even in a case where a best judgment assessment is called for, it is trite law that the estimate should be based on material. The estimate made should have reasonable nexus with the materials on record. The assessing authority found that the excess stock found on the surprise inspection made at the Parma (torn shop worked out to 17% of the book stock for the day; that would have provided a basis for estimating the turnover of that shop. It is probable that there would have been excess stock or other suppression in the other shops as well. But, that is a matter which should be found on the basis of material. The mere fact that there was stock difference of 17% in one of the shops when surprise inspection was made on a day does not mean that there would have been stock difference in the very same shop for the whole year much less at that percentage. It does not also follow that there would have been stock difference in the other shops much less at the same percentage. More than a quarter century ago, the Supreme Court in State of Kerala v. C. Velukutty (17 STC 465), in substantially similar circumstances, laid down the law thus: "From the discovery of secret accounts in the head office, it does not necessarily follow that a corresponding set of secret accounts were maintained in the branch office, though it is probable that such accounts were maintained. But, as the accounts were secret, it is also not improbable that the branch office might not have kept parallel accounts, as duplication of false accounts would facilitate discovery of fraud and, it would have been thought advisable to maintain only one set of false accounts in the head office. Be that as it may, the maintenance of secret accounts in the branch office cannot be assumed in the circumstances of the case. Be that as it may, the maintenance of secret accounts in the branch office cannot be assumed in the circumstances of the case. That apart, the maintenance of secret accounts in the branch office might lead to an inference that the accounts disclosed did not comprehend all the transactions of the branch office. But that does not establish or even probabilise the finding that 135 per cent or 200 per cent or 500 per cent of the disclosed turnover was suppressed. That could have been ascertained from other materials. The branch office had dealings with other customers. Their names were disclosed in the accounts. The accounts of those customers or their statements could have afforded a basis for the best judgment assessment. There must also have been other surrounding circumstances, such as those mentioned in the Privy Council's decision cited supra. But in this case there was ho material before the assessing authority relevant to the assessment and the impugned assessments were arbitrarily made by applying a ratio between disclosed and concealed turnover in one shop to another shop of the assessee. It was only a capricious surmise unsupported by any relevant material." In the light of the above decision, we have no hesitation to hold that the estimate sustained by the Appellate Tribunal is arbitrary and capricious. It is also unreasonable. 8. The Appellate Assistant Commissioner (first appellate authority) held that a lump sum addition of Rs. 1,50000/- will be just and reasonable on account of arrack and an addition of Rs.75,000/- for soda, cola and arishtam will meet the requirements of justice. In the appellate order dated 12-5-1988, he stated thus: "The next dispute is with regard to the addition. Even according to the inspecting officer, the suppression detected on 21-10-1986 that is for the period of 7 months works out to Rs. 17,760/- only for which the addition made is Rs.7,59,302.83. This is really excessive and has no nexus with the turnover detected as suppressed. It is well settled law that the estimate made should have a proper and reasonable relation to the turnover suppressed. Admittedly no such nexus is seen maintained in this case. Moreover it can also be seen that the suppression of Rs.17,760/- detected is for the period of 7 months and if at all an addition is warranted that is to be limited to the next 5 months. Admittedly no such nexus is seen maintained in this case. Moreover it can also be seen that the suppression of Rs.17,760/- detected is for the period of 7 months and if at all an addition is warranted that is to be limited to the next 5 months. The contentions of the appellant in this respect is that the assessing authority has not detected any other variation existed in all days. Moreover it is the case of the appellant that goods dealt with are controlled commodity checked by Excise authorities and except on 21-10-1986 variations has not been found on any day by any authority. Hence the argument of the appellant that "percentage of variation found on a day cannot be applied for the whole year" deserves consideration. According to the appellant the value of the excess stock of arrack is only Rs.36,480/- for this the estimated addition is Rs.6,66,025.83 which is excessive and arbitrary. With regard to the estimate of sales of Soda, Cola, Arishtam the contention of the appellant is that taking 2% of the total sales turnover of arrack is on the higher side. According to the appellant the basis of 2% is not given except that the estimate is reasonable. But the assessing authority is not seen as to how the same is reasonable. So I am of opinion that the addition in this score is also excessive. Considering all the above facts and circumstances of the case and the arguments advanced by the learned authorised representative I think that a lump sum addition of Rs. 1,50,000/- will be more just and reasonable in this case and I order accordingly. So also the addition of Rs.91,677/- made for cola, soda, arishtam is reduced to Rs.75,000/2. In considering the appeals filed by the assessee and the Revenue, the Appellate Tribunal held that in the absence of regular accounts relating to all the 12 shops coupled with the sizable quantum of suppression detected and admitted by the appellant (assessee) especially when the suppression detected related to a single day, the best judgment assessment made by the assessing authority by relying (multiplying) the percentage of suppression detected is found to be proper and legal. The Appellate Tribunal further held that in the light of the decision in Commissioner of Sales tax v. H.M. Esufali H.M. Abdulali (32 STC 77) the interference made by the Appellate Assistant Commissioner is unwarranted and the quantum of addition sustained by the Appellate Assistant Commissioner is not based on any material or basis. We are of the view that the Appellate Tribunal totally ignored the decision of the Supreme Court in Velukutty 's case (17 STC 465) and also overstated the law that on the basis of suppression found out in one of the shops on a single day, the best judgment assessment can be made by the assessing authority by making the percentage of suppression detected as the basis for the whole year and for all the shops. If it is so done, it is a "mechanical" assessment, which is a negation of best judgment assessment. To do so, will be unfair and unreasonable. We are further of the view that in a best judgment assessment, it is primarily for the assessing authority to fix the quantum of estimate to be made in a fair manner and on the basis of material. It is open to the first appellate authority or the second appellate authority to evaluate the basis for the estimate and substitute its own view for the one adopted by the primary authority. In a case where the first appellate authority has, for reasons of its own, set aside the quantum of estimate made by the assessing authority, a duty is cast on the second appellate authority - the Appellate Tribunal - to demonstrate as to how or in what manner the first appellate authority erred in interfering with the estimate made by the assessing authority before substituting its own figure of estimate or restoring the estimate made by the assessing authority. It is true that the Appellate Tribunal is the final fact finding authority. It is an appellate forum on the facts as well as in law. It is the duty of the appellant before the Appellate Tribunal to demonstrate that the order appealed against is wrong. Before reversing a decision of the lower appellate authority a duty is cast on the Appellate Tribunal to meet the reasonings of the first appellate authority and indicate its own reasons for the conclusion to be reached. It is the duty of the appellant before the Appellate Tribunal to demonstrate that the order appealed against is wrong. Before reversing a decision of the lower appellate authority a duty is cast on the Appellate Tribunal to meet the reasonings of the first appellate authority and indicate its own reasons for the conclusion to be reached. The order of the Appellate Tribunal should show that it is for valid and cogent reasons the decision of the first appellate authority is being interfered with. It is not sufficient if the Appellate Tribunal at its ipse dixit states that it disagrees with the decision of the first appellate authority. This Bench had occasion to state the duty of the Appellate Tribunal in cases of reversing the decision of the lower authority and laid down the guidelines on the matter, in Commissioner of Income tax v. NirmalLiquors (190ITR636). 9. We are of the view that the common order passed by the Appellate Tribunal, dated 18-6-1991, is infirm. It is not in accordance with law. It deserves to be set aside. 10. We set aside the common order passed by the Appellate Tribunal, dated 18-6-1991, in T.A.Nos.529 and 671 of 1988 and remit the matter to the Appellate Tribunal for a proper consideration of the appeals in accordance with law and in the light of the observations contained herein above. 11. The Tax Revision Cases are allowed. There shall be no order as to costs.