How can a contract be discharged?

The contract can be discharged in only of the following ways: Obligation unless clearly stated. There are however, exceptions to this rule, e.g. if after frustration, any attempted performance would amount to something quite different from what must have been contemplated by the parties when they made their contract then both partiers are discharged from their obligation of further performance. 

Frustration: Generally, frustration does not discharge contractual. In Tanzania the doctrine of frustration is provided for under section 56(2) of Law of Contract Act. And the effect of the doctrine of frustration for under section 65 read together with proviso of Law of Contract Act.

Performance: Performance must be complete. Contractual obligation is discharged by complete performance of the undertaking.

Agreement: Discharge by agreement is on the principle that a thing may be destroyed in the same manner in which it is constituted that being so, a contractual obligation may be discharged by agreement.

Acceptance of Breach: When the contract is breached, the innocent party may sue for damages and in certain circumstances, he may treat the contract as repudiated by the party in breach and refuse further performance. That is breach by the party and may enable the other party to become discharged from further liability. Be noted that, a contract is not discharged by breach of unless the innocent party elects to meat the breach as a repudiation of contract.