Provisional vs Complete Patent Application — Which Do You File First?

Short answer: file a provisional application to lock in a priority date while your invention is still being finalised; file a complete application when you’re ready for full protection, with formal claims. If you file provisional first, you have 12 months — no extension — to follow up with the complete specification.

The technical difference

Under the Indian Patent Act, 1970, the distinction comes down to one thing: claims.

• A specification with no claims is provisional.
• A specification with claims is complete.

Why file provisional at all?

A provisional application is faster and cheaper to prepare because it doesn’t require finished claims — just a technical description sufficient to establish what you invented and when. This is useful when:

• You want to secure a priority date before a public disclosure, investor pitch, or product launch.
• Your invention is still being refined and formal claims aren’t ready yet.
• You want a lower-cost first step before committing to a full filing.

Read about provisional filing →

The 12-month clock

Once you file provisional, you have exactly 12 months to file the complete specification — this deadline cannot be extended. Miss it, and you lose the priority date the provisional secured. Note also: a provisional filing cannot be used as the basis for a divisional, convention, or PCT national-phase application — those specifically require a complete specification.

What a complete specification adds

A complete specification is the full technical and legal document, including formal claims, that actually defines the scope of protection you’re seeking. It can be filed directly (skipping provisional entirely) or as the required follow-up to a provisional filing. Read about complete specification filing →

Filing internationally?

If you plan to protect your invention outside India too, the PCT (Patent Cooperation Treaty) or Convention route applies — and both require a complete specification, not a provisional one. Read about international/PCT filing →