Explain in detail the discharge of a surety.

The discharge of a surety is one of the most carefully developed areas of the law of guarantee under the Indian Contract Act, 1872. A surety is said to be discharged from liability when his obligation under the contract of guarantee comes to an end — permanently and completely. Since a surety is regarded as a "favoured debtor" and his liability is construed in strictissimi juris — that is, in the strictest possible terms — the law has built around him a comprehensive set of protective provisions spread across Sections 130 to 141 of the Act. The underlying philosophy is simple: the surety undertook to guarantee a specific engagement on specific terms; if those terms are altered, or the creditor undermines the surety's rights, the surety is freed. A careful examination of each mode of discharge follows.

Revocation of a Continuing Guarantee (Section 130)

An ordinary guarantee, once acted upon, cannot be revoked. But Section 130 carves out a special right for the surety in a continuing guarantee — one that extends to a series of transactions — to revoke it at any time as to future transactions by giving notice to the creditor. The revocation takes effect prospectively; the surety remains fully liable for all transactions that have already been entered into before the notice. In Oxford v. Davies (1862), the defendants gave a guarantee for repayment of bills to be discounted over a twelve-month period and revoked it before any bill was discounted. The court held the revocation was valid, and the surety was not liable for the bills subsequently discounted. This section recognises that a surety should not be held perpetually bound to an open-ended obligation when the relationship between the creditor and the principal debtor continues to generate new liabilities.

Death of the Surety (Section 131)

Section 131 treats the death of the surety as an automatic revocation of a continuing guarantee in respect of future transactions, in the absence of any contract to the contrary. The surety's estate remains liable for transactions already completed before death, and his legal heirs can be sued, but only to the extent of the property they have inherited. This rule reflects the deeply personal nature of a guarantee — a creditor cannot expect that a guarantee given by a deceased surety will bind strangers who had no part in giving it.

Discharge by Variance in Terms (Section 133)

This is perhaps the most frequently litigated ground of discharge, and courts have consistently held that it must be applied with vigilance. Section 133 provides that 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.

The foundational principle was expressed with great clarity long ago: a surety enters into a particular and specific contract, and that contract alone binds him. If the original parties change the nature of that contract behind his back, there is nothing left to which he can be bound. As Lord Cottenham put it in Bonar v. Macdonald (1850), where a bank raised a manager's salary and altered his liability for overdraft losses without informing the surety, the surety stood discharged — the fresh agreement was a substitution of a new engagement for the former.

The discharge under Section 133 is not total. The surety remains liable for transactions completed before the variance; he is discharged only as to transactions occurring after it. Unsubstantial alterations that are manifestly to the benefit of the surety may not discharge him. The Supreme Court addressed this in M.S. Anirudhan v. Thomcos Bank Ltd. (AIR 1963 SC 746), where the guaranteed amount was reduced from Rs. 25,000 to Rs. 20,000. The majority held that this insubstantial variation, which actually improved the surety's position, did not discharge him. However, once the alteration is substantial — or even if it is unsubstantial but not self-evidently harmless — the court will not inquire into whether the surety was actually prejudiced. He is the sole judge of that.

The variance must be without the surety's consent. The onus of proving consent lies on the person seeking to enforce the guarantee, and such consent must be informed — the surety must have knowledge of the nature of the variation. If the surety has contractually agreed in the deed of guarantee that variations shall not discharge him, the Karnataka High Court has taken the view that such a waiver is valid, while the Bombay and Punjab High Courts have disagreed, holding that protective provisions cannot be ousted by a general advance consent. This remains a contested area of law.

Discharge by Release of Principal Debtor (Section 134)

Section 134 lays down that the surety is discharged by any contract between the creditor and the principal debtor by which the latter is released, or by any act or omission of the creditor, the legal consequence of which is the discharge of the principal debtor. The rationale is compelling: if the principal debtor is released, the surety loses his right to seek indemnity from the principal debtor after paying the creditor. To hold the surety liable while extinguishing his recourse would be both unjust and fraudulent.

The illustrations to the section capture this beautifully. Where B assigns his property to his creditors including C in exchange for being released from his debts, A — the surety — is discharged. Where B diverts the irrigation water on A's land, thereby preventing A from growing the guaranteed crop of indigo, C the surety is also discharged, because the creditor's act has destroyed the principal debtor's ability to perform.

Critically, the discharge of the principal debtor by operation of law — that is, by insolvency or winding up proceedings — does not absolve the surety. The Supreme Court settled this definitively in Maharashtra State Electricity Board v. Official Liquidator (AIR 1982 SC 1497), holding that when a company goes into liquidation, the surety remains fully liable, because such discharge flows not from any act of the creditor but from the processes of law. Similarly, where the creditor, while releasing the principal debtor, expressly reserves his rights against the surety, the surety is not discharged — for such a "release" is in substance no more than a covenant not to sue the principal debtor, who remains exposed to a suit from the surety.

Discharge by Composition, Extension of Time, or Promise Not to Sue (Section 135)

Section 135 enumerates three separate but conceptually related grounds of discharge. A contract between the creditor and the principal debtor by which the creditor: (i) makes a composition with the principal debtor, (ii) promises to give him time, or (iii) agrees not to sue him, discharges the surety, unless the surety assents to such a contract.

The principle underlying the rule against giving time is rooted in equity. As Lord Eldon explained, the creditor, by giving time to the principal debtor, puts it out of the power of the surety to exercise his own right to compel the creditor to proceed against the principal debtor and thereby protect himself. The creditor has, in effect, tied his own hands behind the surety's back. What constitutes "giving time" is a binding contract to defer the date of payment — not mere passive forbearance to sue. Section 137 separately provides that mere forbearance on the part of the creditor to sue the principal debtor does not discharge the surety. The classic illustration: if the creditor simply delays suing for a year, the surety is not discharged; but if the creditor, in exchange for consideration, binds himself not to sue the principal debtor for a year, the surety is discharged forthwith.

Section 136 provides an important qualification: where the agreement to give time is made by the creditor with a third person — and not with the principal debtor — the surety is not discharged. The rationale is that such an agreement does not alter the principal debtor's obligation or restrict the creditor's right to sue him.

Creditor's Forbearance to Sue (Section 137)

This section, as noted above, ensures that mere delay or passivity on the part of the creditor does not discharge the surety. This is a recognition that a surety himself can, at any point, compel the creditor to proceed against the principal debtor and thereby protect his own interests. The famous Privy Council decision in Mahant Singh v. U Ba Yi (AIR 1939 PC 110) settled — in line with the majority of Indian High Courts — that even if the creditor's forbearance allows the limitation period against the principal debtor to expire, the surety is not discharged. The surety could himself have moved against the principal debtor at any time.

Release of Co-Surety (Section 138)

Where there are co-sureties, the release of one of them by the creditor does not discharge the others. Nor does it release the co-surety so freed from his responsibility to contribute to the other co-sureties. This section protects the orderly working of contribution among co-sureties by ensuring that the creditor's private dealings with one guarantor do not disrupt the obligations of the rest.

Discharge by Impairment of Surety's Remedy (Section 139)

This section operates where the creditor's act or omission, though not legally discharging the principal debtor, nevertheless impairs the surety's eventual remedy against him. Section 139 provides that if the creditor does any act inconsistent with the rights of the surety, or omits to do what his duty requires, and the eventual remedy of the surety against the principal debtor is thereby impaired, the surety is discharged.

The critical distinction between Section 134 and Section 139 is this: Section 134 applies when the creditor's act has the legal effect of discharging the principal debtor; Section 139 applies when it does not technically discharge the principal debtor but destroys the surety's ability to recover indemnity from him after paying the creditor.

The section demands two elements: first, an act or omission inconsistent with the surety's rights; second, that such act or omission actually impairs the eventual remedy of the surety. In State of Madhya Pradesh v. Kaluram (AIR 1967 SC 1105), the Government allowed a forest contractor to remove felled timber before paying the instalments of the contract price. This pre-payment effectively removed the very security — the standing right to withhold timber — on which the surety's eventual right of indemnity depended. The Supreme Court held that the surety stood discharged. Similarly, where a bank negligently allowed pledged goods in its godown to be lost, thereby destroying a security which the surety could have relied on after paying the debt, the surety was discharged to the extent of the value of the lost goods.

Mere passive acquiescence by the creditor — such as failing to supervise an employee whose fidelity is guaranteed — does not discharge the surety. The employer does not guarantee to the surety that he will exercise utmost diligence in checking the employee's work.

Discharge by Loss of Security (Section 141)

Section 141 is the final and perhaps most practically significant provision dealing with the surety's discharge. It provides that the surety is entitled to the benefit of every security which the creditor has against the principal debtor at the time when the contract of suretyship is entered into, whether the surety knows of the existence of such security or not. If the creditor loses or parts with such security without the surety's consent, the surety is discharged — not entirely, but to the extent of the value of the security lost or parted with.

The illustration in the Act captures the rule perfectly: C advances Rs. 2,000 to B guaranteed by A, with the loan also secured by a mortgage on B's furniture. C cancels the mortgage. B becomes insolvent. A is discharged from liability to the extent of the value of the furniture.

The Supreme Court in Amrit Lal Goverdhan Lalan v. State Bank of Travancore (AIR 1968 SC 1432) gave a broad construction to the word "security" under this section — it is not used in any technical sense, but includes all rights which the creditor had against the principal debtor's property at the date of the contract. The section limits the surety's right to securities held by the creditor at the date of the suretyship, distinguishing it from the English rule which entitled the surety to securities given both before and after the guarantee. Importantly, the surety need not first pay the creditor to invoke Section 141 — it operates as a pro tanto discharge even before payment, quite unlike the right of subrogation under Section 140 which requires actual payment.

A discharge under Section 141 requires a deliberate act or a culpable failure on the part of the creditor — mere passive inactivity, or loss of security beyond the creditor's control, does not entitle the surety to discharge.

Taken together, these provisions reflect a coherent philosophy: the surety steps into a defined space of obligation, and the creditor must not, by his own acts or omissions, enlarge that space, diminish the surety's remedies, or alter the very transaction the surety agreed to guarantee. The law treats the surety's position as inviolable except to the extent he himself has accepted a wider or varied burden.