It is common for a single product to pack in hardware, software, algorithms, and a clever user flow. The immediate doubt that follows is whether one must file a single patent or several, each aimed at a different aspect. This choice is not merely strategic, it is grounded in the legal requirement of “unity of the invention”, and it affects cost, timelines, and enforceability across the product’s life cycle.
Unity of the invention, in plain terms
Indian law expects a complete specification to claim a single invention or a group of inventions that are linked by a single inventive concept. If your claims span unrelated problem–solution pairs, the Patent Office can insist that you split the case. The text of Section 10(5) of the Patents Act states this requirement explicitly.
How to apply this in real life
If different “aspects” solve one central technical problem together, they can often live inside one application as separate independent claims.
If aspects solve distinct problems or require materially different prior art analyses, the unity link is likely weak. Prepare to separate them.
For drafting, use a clear problem–solution narrative in the description, and claim each linked aspect explicitly to show the single inventive concept.
If different “aspects” solve one central technical problem together, they can often live inside one application as separate independent claims.
If aspects solve distinct problems or require materially different prior art analyses, the unity link is likely weak. Prepare to separate them.
For drafting, use a clear problem–solution narrative in the description, and claim each linked aspect explicitly to show the single inventive concept.
One patent with broader claims or several patents?
A single application can carry multiple independent claims to cover the device, method, and system, provided unity holds. This is a legitimate approach to cover complementary aspects without fragmentation. If claims start pulling in different technical directions, separate filings are safer.
Quick comparative guide
Keep it in one patent when aspects are functionally tied to the same inventive core and share overlapping distinguishing features over prior art.
File separate patents when aspects are independently novel and inventive, address different technical problems, or would likely face distinct prior art.
Keep it in one patent when aspects are functionally tied to the same inventive core and share overlapping distinguishing features over prior art.
File separate patents when aspects are independently novel and inventive, address different technical problems, or would likely face distinct prior art.
When to split: divisional applications under Section 16
If an application contains a plurality of inventions, you may file a divisional application. A divisional keeps the parent’s priority date for the carved-out claims and is examined separately. Historically, practice was restrictive, but recent jurisprudence has clarified two important points.
Two key Delhi High Court decisions
Boehringer Ingelheim v. Controller (2022, Delhi HC) took a narrow view on divisionals when plurality was not found in the parent’s claims.
Syngenta Ltd. v. Controller (2023, Delhi HC, Division Bench) clarified that plurality can be found in what is disclosed in the specification and is not confined only to what the parent happened to claim. It also affirmed that applicants may file a divisional suo motu, even without a unity objection from the Controller. This broadened practical room for applicants to protect different disclosed embodiments.
Boehringer Ingelheim v. Controller (2022, Delhi HC) took a narrow view on divisionals when plurality was not found in the parent’s claims.
Syngenta Ltd. v. Controller (2023, Delhi HC, Division Bench) clarified that plurality can be found in what is disclosed in the specification and is not confined only to what the parent happened to claim. It also affirmed that applicants may file a divisional suo motu, even without a unity objection from the Controller. This broadened practical room for applicants to protect different disclosed embodiments.
Do I need a unity objection to file a divisional?
No. After Syngenta (2023), a suo motu divisional is maintainable if the parent discloses a plurality of inventions, even if the claims did not originally separate them. The test is whether the divisional’s claims are fairly based on the parent’s disclosure and reflect a distinct invention.
Timing trap: “before grant” means what in practice?
Section 16 requires filing a divisional before grant of the parent. The Madras High Court in BASF SE v. Deputy Controller (2024) addressed a practical quandary, holding that filing a divisional on the same day as grant can satisfy “before grant”, given that applicants cannot know the precise moment of grant. The refusal for being filed “after grant” on the same day was quashed and remanded. This eases timing anxiety where the IPO does not flag the grant time in advance.
Practical steps for divisionals
Identify all distinct embodiments early. Map each to problem–solution and distinguishing features.
If in doubt, prepare a divisional shell well before final allowance, so filing can be triggered quickly.
Avoid overlapping claim scope between parent and divisional to prevent double patenting challenges later.
Identify all distinct embodiments early. Map each to problem–solution and distinguishing features.
If in doubt, prepare a divisional shell well before final allowance, so filing can be triggered quickly.
Avoid overlapping claim scope between parent and divisional to prevent double patenting challenges later.
Improvements to the same product: consider a Patent of Addition
If, after filing or grant of the main patent, you develop an improvement or modification of the same invention, Indian law offers a Patent of Addition under Sections 54 to 56. Key features:
It rides on the main patent and shares its remaining term.
There are no separate renewal fees while it remains a patent of addition.
It can be converted into an independent patent if the main patent is revoked.
The statute protects a patent of addition from invalidation merely for lack of inventive step over the main invention, though it must still be novel.
Courts have discussed patents of addition in Ravi Kamal Bali v. Kala Tech (Bombay HC, 2008), underscoring their linkage to an existing invention and their utility where the improvement is anchored to the patented core. For incremental enhancements to the same product, this route is often leaner than a fresh independent filing.
It rides on the main patent and shares its remaining term.
There are no separate renewal fees while it remains a patent of addition.
It can be converted into an independent patent if the main patent is revoked.
The statute protects a patent of addition from invalidation merely for lack of inventive step over the main invention, though it must still be novel.
Is a patent of addition right for me?
Choose this route when the improvement is tightly connected to the main inventive concept and offers incremental advancement best enforced alongside the main patent. If the improvement solves a different technical problem or would stand strong on novelty and inventive step independently, consider a separate patent.
Beware of double patenting
While the Act does not carry a standalone “double patenting” section, Indian courts have been clear that the same product cannot be covered by multiple patents of the same applicant where claims are not patentably distinct. In AstraZeneca AB v. Intas (Delhi HC, 2021) concerning dapagliflozin, the court refused interim relief noting that the species patent could not extend exclusivity where the same product was already covered by the genus patent’s claims. The ratio is simple: one product should not enjoy two overlapping patent monopolies. Align your claim sets across related filings to keep them patentably distinct.
FAQs woven into strategy
Can I file multiple patents for different aspects now, or should I start with one and divide later?
Start with one application if unity is defensible and you want a cohesive prosecution. If distinct aspects emerge or strategy shifts, use a divisional before grant to ring-fence each invention. Post-grant improvements may fit a patent of addition. Keep an eye on overlapping claims to avoid double patenting issues. Syngenta (2023) makes it easier to carve out disclosed but unclaimed embodiments into a divisional when needed.
Can I rely on PCT unity standards when I enter India?
Broadly, yes. India’s unity framework mirrors PCT Rule 13.1 and the “single general inventive concept” test, but national examiners will apply Indian practice and case law during examination. Expect India-specific scrutiny on how your claims knit together around the inventive concept.
What if the IPO never raised a unity objection in the parent?
You can still file a divisional on your own initiative if the specification supports a distinct invention that was not pursued in the parent’s claims, as clarified by Syngenta (2023). File it before grant and ensure non-overlap with the parent’s claims.
A practical filing playbook for multi-aspect products
1) At the drafting desk
Write the description to present a clear core inventive concept and map each “aspect” to that core.
Decide early: one specification with multiple independent claims versus parallel specifications.
Pre-draft claim sets that could live in a future divisional if unity is later questioned.
2) During prosecution
Track grant signals closely. If you plan a divisional, avoid cutting it too close to grant. The BASF ruling is helpful but treat same-day filings as a last resort.
Keep claim scopes in related cases patentably distinct to sidestep double patenting challenges, taking cues from AstraZeneca v. Intas.
3) Roadmap for improvements
For incremental tweaks to the same product, use patents of addition to extend your enforcement surface without extra annuities and with shared term.
Bottom line
Yes, you can file multiple patents for different aspects, but do it deliberately. Use unity to keep truly linked aspects together, deploy divisionals to separate distinct inventions before grant, reserve patents of addition for incremental improvements, and maintain clear daylight between claim sets to avoid double patenting.
Write the description to present a clear core inventive concept and map each “aspect” to that core.
Decide early: one specification with multiple independent claims versus parallel specifications.
Pre-draft claim sets that could live in a future divisional if unity is later questioned.
Track grant signals closely. If you plan a divisional, avoid cutting it too close to grant. The BASF ruling is helpful but treat same-day filings as a last resort.
Keep claim scopes in related cases patentably distinct to sidestep double patenting challenges, taking cues from AstraZeneca v. Intas.
For incremental tweaks to the same product, use patents of addition to extend your enforcement surface without extra annuities and with shared term.
