JUDGMENT S.K. Katriar, J: The Bihar State Electricity Board has preferred this appeal under Clause 10 of the Letters Patent of the High Court of Judicature at Patna, and is aggrieved by the order dated 12.03.2004, passed by a learned Single Judge of this Court in C.W.J.C. No. 5391 of 2002, whereby the writ petition preferred by respondent no.1 herein has been allowed, and it has been held that the amount of interest in terms of section 17 of the Bihar & Orissa Public Demand Recovery Act (hereinafter referred to as “the Act”), is not realizable from respondent no.1. 2. A brief statement of facts essential for disposal of the present appeal may be indicated. Paras Nath Singh, the writ petitioner ( respondent No.1 herein), owns a cold-storage and was purchasing electricity from the appellant. In view of his failure to pay the electricity bills, the Board sent a requisition to the learned Certificate Officer-cum- Subdivisional Officer, Sonepur, Saran, for realization of a sum of Rs. 7,80,885.95, from respondent no.1, as a public demand within the meaning of the Act. The certificate was signed in October, 1993. Respondent no.1 started depositing the amount in instalments. During the course of certificate proceeding, respondent no.1 submitted an application that the Board had made the requisition in excess of the actual demand and it should be reduced. The concerned Electrical Executive Engineer sent his communication dated 04.05.2000, to the General Manager-cum- Chief Engineer, Tirbut Area Electricity Board, Muzaffarpur (Annexure-3), stating therein that the original amount may be reduced by Rs. 1,55,036.54. This communication was noticed by the learned Certificate Officer in his order dated 04.07.2000 (Annexure-2). Respondent no.1 deposited the principal amount in instalments, and the last instalment of Rs. 1,25,850/- was deposited with the learned Certificate Officer on 04.11.2000, completing the sum of Rs. 6,25,849.41. The learned Certificate Officer thereafter passed the order dated 30.07.2001, stating therein that the entire principal amount after rectification of the certificate has been deposited by the certificate debtor in instalments, and recorded that interest had to be realized. 1,25,850/- was deposited with the learned Certificate Officer on 04.11.2000, completing the sum of Rs. 6,25,849.41. The learned Certificate Officer thereafter passed the order dated 30.07.2001, stating therein that the entire principal amount after rectification of the certificate has been deposited by the certificate debtor in instalments, and recorded that interest had to be realized. The order is reproduced hereinbelow: <span class="Hfont"> Þnsunkj vfEcdk dksYM LVksjst] u;kxk¡o ls eqy jkf'k dh olqyh dh xbZ gSA eqy jkf'k ij lqn dh jkf'k dh olqyh fu;ekuqlkj djuh gSA bl lEcU/k esa fo|qr v/kh{kd vfHk;ark] fo|qr vapy Nijk rFkk lgk;d fo|qr vfHk;ark] lksuiqj ls i=kpkj fd;k x;k gS ijUrq mDr foHkkx ls i=ksRrj izkIr ugha gqvkA vr% fo|qr v/kh{k.k vfHk;ark] Nijk rFkk lkg;d fo|qr vfHk;ark] lksuiqj dks lekfjr djsaAÞ 3. The petitioner challenged the impugned order of the learned Subdivisional Officer-cum-Certificate Officer by preferring the present C.W.J.C. No.5391 of 2002. The same has been allowed mainly on the ground that interest in terms of section 17 of the Act can be realized only after the certificate has been signed. Learned Single Judge has further observed that the certificate not having been signed, interest cannot be realized from the certificate debtor, and has accordingly allowed the writ petition. Thus, interest cannot be realized from the certificate debtor. Hence this appeal at the instance of the Board. 4. We have perused the materials on record and considered the submissions of the learned counsel for the parties. Thus, interest cannot be realized from the certificate debtor. Hence this appeal at the instance of the Board. 4. We have perused the materials on record and considered the submissions of the learned counsel for the parties. We are of the view that the aforesaid letter dated 24.06.2000 of the Electrical Executive Engineer, whereby he took steps for rectification of the certificate, was noticed by the learned Certificate Officer in his order dated 04.07.2000, which is reproduced hereinbelow: <span class="Hfont"> ÞesllZ vfEcdk dksYM LVksjst] u;kxk¡o dh vksj ls ,d vkosnu i= ds lkFk fo|qr v/kh{k.k vfHk;ark Nijk ds i=kad 1625 fn0 24-6-2000 dh Nk;kizfr fn;k x;k gSA vkosnu i= ij fo}ku vf/koDrk dk gLrk{kj gSA fo}ku vf/koDrk dks lwukA mUgksaus eks0 50]000 ipkl gtkj :i;k tek djus dk vuqjks/k fd;k gSA dqy fdruh jkf'k nsunkj ls olwyh djuh gSA fo|qr v/kh{k.k vfHk;ark] Nijk rFkk lgk;d fo|qr vfHk;ark] lksuiqj dks i= fy[ksaA vuqeaMy ukthj nsunkj ls eks0 50]000 ipkl gtkj :i;k tek dj jlhn fuxZr djsaA fn0 22-9-2000 dksAÞ 4.1 We are of the view that the order is inartistically worded, but in substance means that the certificate stood rectified and stood reduced to the extent of Rs. 50,000/-. We, therefore, take it that the order dated 04.07.2000 is the date of rectification of the certificate in terms of section 11 of the Act. Law is well settled that rectification of pleadings, for example, amendment in the plaint, dates back to the date of institution of the suit. In that view of the matter, the rectification sought to be done by the communication dated 24.06.2000, dates back to October 1993. Resultantly the certificate will be deemed to have been signed in October 1993. 5. In this connection we would like to notice section 17 of the Act, which is reproduced hereinbelow: 1[ 17. Interest, costs and charges recoverable.- There shall be recoverable, in the proceedings in execution of every certificate filed under this Act,- 2[(a) interest upon the public demand to which the certificate relates at the rate of twelve per centum per anum from the date of the signing of the certificate up to the date of realization, (b) such costs are directed to be paid under Section 45, and (c) all charges incurred in respect of- (i) the service of notice under Section 7 and of warrants and processes’ (ii) all other proceedings taken for realizing the demand. It is evident on a plain reading of the same that interest upon the public demand shall be realized @ 12 % per annum from the date the certificate is signed, up to the date of realization. Section 17 of the Act is in mandatory terms and the certificate officer has no discretion or option in the matter. Applying the same to the facts and circumstances of the present case, the rate of interest @ 12% per annum shall be paid from October, 1993 to 04.11.2000. It must be made clear that interest stopped accruing on the amounts deposited in instalments from time to time. Principal interest shall be leviable only on the balance of the principal amount. 6. In the result, we respectfully disagree with the order of the learned Single Judge. This appeal is accordingly allowed. The learned Certificate Officer shall proceed to realize the amount of interest accordingly. We direct the learned Certificate Officer to recalculate the amount of interest which the certificate debtor shall pay within a period of four months of service of the supplementary demand notice. I agree.