Sections 18 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
Section 18 makes every partner the agent of the firm for the purposes of the firm's business. Section 19 says what that means for outsiders: an act done to carry on, in the usual way, business of the kind the firm carries on binds the firm, and it lists eight acts that implied authority does not cover unless there is a usage or custom of trade.
Subject to the provisions of the Act, a partner is the agent of the firm for the purposes of its business (section 18). The act of a partner done to carry on, in the usual way, business of the kind carried on by the firm, binds the firm (19(1)), subject to section 22. This is the partner's implied authority. Unless a usage or custom of trade says otherwise, implied authority does not extend to eight listed acts, such as submitting a dispute to arbitration, opening a bank account in his own name, or acquiring or transferring immovable property (19(2)). The partners can extend or restrict implied authority by contract under section 20.
Section 18: the partner as agent
Section 18 is one sentence. Subject to the provisions of this Act, a partner is the agent of the firm for the purposes of the business of the firm.
Two ideas sit in it:
- Agency. A partner acts for the firm, so what he does within his role is treated as done by the firm. This is why the firm, and through it the other partners, can be held to a deal that one partner signs. The firm's liability for such acts is dealt with in sections 25 to 27.
- Limited to the firm's business. The agency is for "the purposes of the business of the firm". It is not a general authority to do anything.
If you are unsure how far a partner's signature binds your firm, a short legal consultation can help you map the risk before a dispute arises.
Section 19(1): the general rule
Subject to section 22, the act of a partner which is done to carry on, in the usual way, business of the kind carried on by the firm, binds the firm. The authority of a partner to bind the firm under this section is called his implied authority.
Break the rule into its tests:
| Test | Meaning |
|---|---|
| Act of a partner | Something done by one of the partners |
| To carry on business | Done for running the firm's business |
| Of the kind carried on by the firm | The type of business the firm actually does |
| In the usual way | Done as such a business ordinarily does it |
| Subject to section 22 | The act must also be done in the manner section 22 requires; see sections 22 to 24 |
Example. A, B and C run a grocery wholesale firm. B orders 100 bags of rice for Rs 2 lakh from a regular supplier, in the firm's name. Ordering stock is business of the kind the firm carries on, done in the usual way, so it binds the firm. If B instead ordered a fleet of trucks for a transport business the firm does not carry on, the "kind of business" test is not met.
Section 19(2): acts not covered by implied authority
Section 19(2) opens: in the absence of any usage or custom of trade to the contrary, the implied authority of a partner does not empower him to do any of the following:
| Clause | Act outside implied authority |
|---|---|
| (a) | Submit a dispute relating to the business of the firm to arbitration |
| (b) | Open a banking account on behalf of the firm in his own name |
| (c) | Compromise or relinquish any claim or portion of a claim by the firm |
| (d) | Withdraw a suit or proceeding filed on behalf of the firm |
| (e) | Admit any liability in a suit or proceeding against the firm |
| (f) | Acquire immovable property on behalf of the firm |
| (g) | Transfer immovable property belonging to the firm |
| (h) | Enter into partnership on behalf of the firm |
Points to note:
- Usage or custom of trade can change the position. The opening words allow a contrary usage or custom of trade. The text does not say what counts as a usage or how it is proved.
- These are limits on implied authority only. The partners can give a partner more authority by contract; see sections 20 and 21.
- Practical reading. The list covers serious steps that can commit the firm heavily or give up its claims: legal decisions (a, c, d, e), banking in a partner's own name (b), land and buildings (f, g), and bringing in a new partner (h).
Example. Dinesh, one of three partners in a trading firm, signs a settlement giving up Rs 3 lakh of a Rs 5 lakh claim against a customer, without telling the others. Under 19(2)(c), his implied authority does not by itself empower him to compromise or relinquish a claim or part of it. Whether the firm is bound would depend on whether he had actual authority from the partners or on a contrary usage of trade, and on how section 20 operates for outsiders.
What can the deed change?
Section 18 begins "subject to the provisions of this Act" and section 19(1) is "subject to section 22". Neither is introduced by the words "subject to contract between the partners". The contract's role comes through section 20, which allows the partners to extend or restrict implied authority between themselves. So:
| Matter | Position |
|---|---|
| Agency of each partner | Stated by section 18 |
| Implied authority under 19(1) | Can be extended or restricted by contract under section 20, though a restriction does not always protect the firm against outsiders |
| The eight exclusions in 19(2) | Apply in the absence of a contrary usage or custom of trade; the partners can give authority by contract |
A deed that lists who may sign cheques, order goods or settle claims, and up to what amount, reduces the risk. Our partnership deed drafting service can set these limits out.
Practical points
- Write down signing limits. For example, any two partners to sign contracts above Rs 5 lakh.
- Record authority for litigation. Because 19(2) excludes arbitration, compromise, withdrawal and admissions, get written authority from the partners before taking those steps for the firm.
- Use the firm name. Section 19(1) is subject to section 22, which looks at how the act is done.
- Property and banking. Passing a resolution is sensible before buying or selling land or opening bank accounts.
- Admitting a partner. Clause (h) means one partner cannot, by implied authority alone, bring in another; see also section 31.
Need help sorting out who can bind your firm?
If you are worried that a partner's actions may commit the firm, or you need to know what to do after an unauthorised deal, our legal consultation service can review the facts and your deed and explain your options.
Key takeaways
- Every partner is the agent of the firm for the purposes of its business (section 18).
- An act done to carry on, in the usual way, business of the kind carried on by the firm binds the firm (19(1)).
- Implied authority does not cover eight listed acts, absent a contrary usage or custom of trade (19(2)).
- The partners can extend or restrict implied authority by contract (section 20).
- Section 19(1) is subject to section 22 on how the act is done.
Read next
- Sections 16 and 17: personal profits and rights after a change in the firm
- Sections 20 and 21: restricting implied authority and authority in an emergency
- Sections 22 to 24: acts binding the firm, admissions and notice to a partner
- Rights of partners under the Partnership Act
Disclaimer: Based on the text of the Indian Partnership Act, 1932 as consulted on 1 October 2026. Several States have amended the registration chapter and make their own rules, forms and fees for the Registrar of Firms. This article is general information, not legal advice; check the official text and your State's rules before acting.