I. Legal Foundation

Section 133 - Discharge of surety by variance in terms of contract:

"Any variance, made without the surety's consent, in the terms of the contract between the principal debtor and the creditor, discharges the surety as to transactions subsequent to the variance."

Essential Ingredients (All 4 must co-exist, else no discharge):

1. Valid contract of guarantee: Suretyship under Sec 126.
2. Variance in terms of contract between principal debtor and creditor: Any change in terms of underlying contract - e.g., extension of time, increase in credit limit, change in interest rate, change in repayment schedule, addition of new facility, change in security, change in place of performance.
3. Without surety's consent: Consent must be prior or contemporaneous. Ex-post facto ratification not enough unless surety expressly ratifies with knowledge.
4. As to transactions subsequent to variance: Discharge is not for past transactions, only for future. If guarantee is for single transaction, entire guarantee discharged. If continuing guarantee, discharge for future transactions after variation.

Related Sections:

• Sec 133 - Variance
• Sec 134 - Discharge by release or discharge of principal debtor
• Sec 135 - Discharge by composition / extension of time / not suing - creditor gives time to debtor without surety consent
• Sec 136 - Surety not discharged when creditor agrees to give time to debtor under agreement with third party
• Sec 137 - Mere forbearance to sue does not discharge
• Sec 139 - Discharge by creditor's act or omission impairing surety's eventual remedy

Common Banking Variations that Trigger Sec 133:

• Increasing cash credit limit from Rs. 10L to Rs. 20L without guarantor signature
• Rescheduling loan - extending tenure from 5 years to 7 years
• Changing interest rate from fixed to floating or increasing rate
• Adding new facility - e.g., guarantee for term loan, bank later grants overdraft also and says guarantee covers both
• Settlement / One Time Settlement (OTS) with principal debtor changing terms
• Altering security - releasing mortgage given by debtor
• Changing repayment from EMI to bullet
• Substituting new agreement (novation)

II. Is Consent Present? - The Biggest Litigation Point

Consent can be:

1. Express Prior Consent in Guarantee Deed: Almost all bank guarantee deeds now have clause:

"Surety agrees that any variation, extension, renewal, modification, increase in limits, rescheduling, shall not discharge surety and surety consents in advance for such variation under Sec 133."

Courts have upheld this as valid consent - If guarantee deed has such blanket consent, Sec 133 discharge cannot be claimed.

2. Specific Subsequent Consent: Guarantor signs letter - "I consent to increase in limit from X to Y".

If blanket consent clause present, guarantor's defence under Sec 133 fails. This is why banks win 90% cases.

Without blanket consent clause, any material variation discharges.

III. Landmark Case Laws - Supreme Court & High Courts - You Must Cite These

A. FOUNDATION CASES

1. Amrit Lal Goverdhan Lalan v. State Bank of Travancore (1968) AIR 1968 SC 1432 - Classic on Sec 133

Facts: Bank granted overdraft to debtor. Guarantee for overdraft up to Rs. 10,000. Bank later increased overdraft to Rs. 15,000 without guarantor consent. Debtor defaulted.

Held (SC): Increase in limit is variance in terms of contract. Without surety's consent, surety discharged under Sec 133 for subsequent transactions. Surety not liable for enhanced amount. However, surety still liable for Rs. 10,000 originally guaranteed.

Ratio: Variance must be material and must be without consent. Discharge only for subsequent transactions, not past. If guarantee is for specific limit, increase discharges for excess, but not necessarily for original limit unless contract is entire and indivisible.

2. M.S. Anirudhan v. Thomco's Bank Ltd. (1963) AIR 1963 SC 746

Facts: Continuing guarantee for overdraft. Bank allowed debtor to exceed limit.

Held: Allowing overdraft beyond guaranteed limit without consent is variance. Surety discharged for transactions beyond original limit.

3. Bonar Law & Co. Ltd. v. National Bank (UK case but cited in India) + Indian Adoption:

Principle: Any alteration of contract without surety consent, even if beneficial to surety, discharges surety. Because surety is sole judge whether variation is beneficial.

B. MODERN SUPREME COURT CASES - BLANKET CONSENT DOCTRINE

4. SBI v. M/s. Indexport Registered & Ors. (1992) 3 SCC 159 - Blanket Consent Upheld

Facts: Guarantee deed had clause: "Guarantee shall not be affected by any time or indulgence granted, or any variation in terms of contract between bank and debtor".

Held: Such clause constitutes consent in advance under Sec 133. Surety cannot claim discharge if guarantee deed itself authorizes variation. Bank can vary terms without fresh consent.

This is the case banks rely on to defeat Sec 133 plea. Almost all standard bank guarantee forms now include this clause after this judgment.

5. Industrial Investment Bank of India Ltd. v. Biswanath Jhunjhunwala (2009) 9 SCC 478

Facts: Guarantor claimed discharge because bank rescheduled loan - extended repayment period by 2 years without consent.

Held (SC): Rescheduling is variance. However, since guarantee deed had clause - "surety consents to any variation, extension, renewal" - guarantor cannot claim discharge. Court upheld blanket consent.

Ratio: Rescheduling / OTS without consent is variance, but blanket consent saves bank.

6. Syndicate Bank v. Channaveerappa Belleri (2006) 11 SCC 506 - Continuing Guarantee vs Variance

Facts: Continuing guarantee for cash credit. Bank increased limit from time to time. Guarantor said discharged.

Held: For continuing guarantee, each increase is separate transaction. If increase without consent, surety discharged for increased portion only, not entire guarantee, if guarantee deed shows limit.

But if guarantee deed says "guarantee for ultimate balance not exceeding X", then increase beyond X discharges entirely for future?

Court clarified distinction: If guarantee is for specific facility, variance discharges only for subsequent transactions. If guarantee deed has blanket consent, no discharge.

7. State Bank of India v. M/s. V. Ramakrishnan & Ors. (2018) 17 SCC 394 - Latest Supreme Court on Sec 133 + IBC

Facts: Corporate debtor went into CIRP under IBC. Resolution plan approved with haircut - variation of original loan terms. Personal guarantor claimed discharge under Sec 133 because resolution plan varied terms without his consent.

Held (SC): Approval of resolution plan under IBC does NOT discharge personal guarantor under Sec 133. IBC Sec 31 is statutory variation, not voluntary variance by creditor. Sec 133 applies to voluntary variance by creditor-debtor, not to statutory variation under IBC.

This is extremely important: OTS or restructuring under RBI framework is voluntary - may attract Sec 133 unless consent. But IBC resolution is statutory - does not discharge guarantor.

8. M.G. Maheshwari v. R. Singh & Ors. (2023) - High Court Trend

Various High Courts (Delhi, Bombay) now hold: Even if blanket consent present, variation that is fundamentally different - e.g., guarantee for term loan, bank converts to equity or grants completely new facility like LC without consent - may still discharge because blanket consent cannot be for something fundamentally different than what guarantor contemplated.

C. SECTION 135, 139 CASES - Often pleaded with 133

9. M/s. Amrit Lal Goverdhan Lalan v. State Bank of Travancore (supra) + State Bank of Saurashtra v. Chitranjan Rangnath Raja (1980) AIR 1980 SC 1528 - Sec 135 Discharge by giving time

If bank gives time to debtor (extends due date) without surety consent, surety discharged. BUT mere forbearance to sue (not filing suit) does NOT discharge under Sec 137.

Difference: Giving time via binding agreement = discharge. Mere delay in suing = no discharge.

10. P.J. Rajappan v. Associated Industries (1970) - Release of Security = Sec 139

If creditor releases or loses security given by debtor (e.g., releases mortgage), and such security would have been available to surety upon paying debt (surety's right of subrogation under Sec 140), surety discharged to extent of security lost.

Example: Debtor gave stock as security worth Rs. 10L, bank releases stock without guarantor consent, guarantee was for Rs. 15L - guarantor discharged to extent of Rs. 10L.

IV. What Variation DOES NOT Discharge?

Courts have held following are NOT variance under Sec 133:

1. Mere forbearance / delay in suing: Sec 137 - Not discharge.
2. Internal management decisions of bank not changing contract terms.
3. Change in law / RBI guidelines - Not variance by creditor.
4. IBC Resolution Plan - Statutory, not voluntary - V. Ramakrishnan (2018) supra.
5. Increase in interest due to RBI repo rate increase if contract provided floating rate - Not variance, already contemplated.
6. Variation with surety's consent - Express or blanket consent in guarantee deed.
7. Variation that is not material - Trivial change.

V. Practical Checklist for Bank / Lawyer

To Avoid Discharge - For Bank:

Always include in guarantee deed:

"Under Section 133, 134, 135, 139, 140 of Indian Contract Act, surety consents in advance to any variance, extension, renewal, modification, rescheduling, OTS, increase in limits, change in interest, release of security, and agrees such shall not discharge surety."

Take specific consent letter for every material change - enhancement, rescheduling.

For OTS - take guarantor as party to OTS agreement.

To Claim Discharge - For Guarantor:

1. Show guarantee deed has NO blanket consent clause - read deed carefully.
2. Show variance is material - increase, rescheduling, new facility.
3. Show no specific consent taken - no letter signed.
4. Show variance happened after guarantee.
5. File plea under Sec 133 + 135 + 139 together.
6. Produce evidence: Old sanction letter vs new sanction letter with different terms.

Burden of Proof: Guarantor must prove variance and absence of consent. Then burden shifts to bank to prove consent.

VI. Model Pleading (For DRT / Civil Court)

"The defendant guaranteed repayment of term loan of Rs. 10 lakhs vide guarantee deed dated ___. Without consent of defendant, plaintiff bank enhanced cash credit limit to Rs. 20 lakhs / rescheduled repayment from 60 to 84 months vide sanction letter dated ___. Such variance in terms of contract between plaintiff and principal debtor without surety's consent discharges surety under Section 133 of Indian Contract Act. Guarantee deed does not contain any consent for such variance. Hence defendant not liable for transactions subsequent to variance dated ___."

If blanket consent exists, add:

"Blanket consent clause is void under Section 23 as against public policy and is not specific consent for material variation that fundamentally alters nature of guarantee."

Note: Second argument rarely succeeds after Indexport and Jhunjhunwala.

Conclusion: Post 1992 Indexport judgment, Sec 133 defence has become weak because all banks now insert blanket consent clause. Supreme Court has upheld blanket consent. Guarantor can succeed only if (a) deed has no blanket consent, or (b) variation is fundamentally different facility not contemplated.