Initially Published 2019: Updated in Feb 2026
What Is WIPO DAS? Priority Document System for PCT Applications
The WIPO Digital Access Service (DAS) is an electronic system that allows participating intellectual property offices to exchange certified copies of priority documents securely. Instead of preparing and transmitting paper certified copies to each office individually, the priority document is deposited once and retrieved electronically by offices of second filing.
For Indian applicants filing a PCT international application that claims priority from an Indian patent application, WIPO DAS provides the primary electronic route for furnishing the priority document to the International Bureau (IB). Once the Indian Patent Office (IPO) deposits the certified copy in the DAS system, the IB can retrieve it using a unique DAS access code. This eliminates the need for courier transmission or separate certified copy requests for each jurisdiction.
As of March 2026, more than 50 intellectual property offices participate in WIPO DAS, including the Indian Patent Office, which acts both as a depositing office and an accessing office.
Furnishing the priority document within the applicable deadline is critical. If the certified copy is not properly furnished under the PCT framework, the priority claim may be disregarded by designated offices, potentially affecting the effective prior art date of the application.
In practical terms, the workflow is straightforward. The Indian Patent Office uploads the certified copy of the priority application once, and participating offices retrieve it electronically using the DAS access code. This removes the administrative burden associated with paper certified copies.
This guide explains how WIPO DAS operates in relation to Indian priority applications, including:
- how Indian applicants deposit priority documents with the IPO before filing a PCT application, and
- how foreign applicants or international counsel retrieve Indian priority documents when the IPO acts as an accessing office.
Fees reference in this article are based PCT Applicant’s Guide India, valid from 1 January 2026. Participation statistics are sourced from the WIPO DAS Participating Offices page, accessed 30 March 2026.
Priority Document Submission Options for PCT Applications (Rule 17.1 Explained)
PCT Rule 17.1 sets out the mechanisms by which an applicant furnishes a certified copy of the priority document to the International Bureau (IB). Which route applies depends largely on where the PCT international application is filed and whether the priority document is available through the WIPO Digital Access Service (DAS).
Rule 17.1(a): Direct submission of the certified copy
Under Rule 17.1(a), the applicant furnishes a certified copy of the priority document directly to the receiving office or to the International Bureau. The certified copy must be submitted no later than 16 months from the priority date.
This method is available in all cases and functions as the default route where no electronic retrieval mechanism is used.
Rule 17.1(b): Transmission by the receiving office
Rule 17.1(b) applies where the receiving office and the office of first filing are the same. In such cases, the applicant may request the receiving office to prepare and transmit the certified copy to the International Bureau.
For Indian applicants filing the PCT application at RO/IN, this is typically the most direct route. The request is made by selecting the appropriate option in Box No. VI of Form PCT/RO/101, after which the Indian Patent Office prepares and transmits the certified copy to the IB. No DAS access code is required for this mechanism.
Rule 17.1(b-bis): Retrieval through WIPO DAS
Rule 17.1(b-bis) allows the International Bureau to retrieve the priority document electronically through WIPO DAS. Two conditions must be satisfied:
- the priority document must already be available in the WIPO DAS system, and
- the International Bureau must be instructed to retrieve the document before the date of international publication.
Depositing the document in WIPO DAS alone does not fulfil the priority document requirement unless the IB is also instructed to retrieve it.
This route becomes particularly relevant when the PCT application is filed at RO/IB or another receiving office different from the office of first filing, because Rule 17.1(b) is not available in that situation. Where an Indian applicant files the PCT application at RO/IB and claims priority from an Indian patent application, WIPO DAS provides the most practical mechanism for furnishing the priority document unless the applicant instead submits a certified copy directly under Rule 17.1(a).
In practice, many practitioners still request a DAS deposit even when filing at RO/IN, since the deposit creates a reusable record that can be relied upon in later PCT or Paris Convention filings claiming the same Indian priority application.
According to the WIPO DAS Working Group Status Report (February 2025), the International Bureau retrieved 158,119 patent priority documents for PCT applications through WIPO DAS in 2024, accounting for more than 40 percent of all DAS retrievals that year.
How WIPO DAS Works for an Indian Priority Application
For an Indian patent application used as the priority document for a PCT international application, the WIPO DAS process typically follows five steps:
- File the Indian patent application at the Indian Patent Office (IPO).
- Submit a DAS deposit request through the IPO e-filing portal and pay the prescribed fee under Entry No. 49 of the First Schedule to the Patents Rules, 2003.
- Receive the DAS access code by email once the IPO uploads the certified copy of the application to the WIPO DAS system.
- Enter the DAS access code when filing the PCT application—either in the Priority Claims section of ePCT or in Box No. VI of Form PCT/RO/101 for paper filings.
- Instruct the International Bureau (IB) to retrieve the document from WIPO DAS before international publication.
Once retrieval is completed, the International Bureau confirms this through Form PCT/IB/304.
WIPO DAS India: Procedure for Depositing a Priority Document at the Indian Patent Office
When an Indian patent application will serve as the priority document for a future PCT international application, the applicant should request the Indian Patent Office (IPO) to deposit a certified copy of the application into the WIPO DAS system before filing the PCT application.
The IPO deposits patent applications filed on or after 31 January 2018, but only upon an explicit request from the applicant. Although industrial design applications may also be deposited in WIPO DAS under a separate framework, this article focuses exclusively on patent applications used as PCT priority documents.
The deposit request is submitted through the IPO e-filing portal. Unlike certain offices such as the USPTO, the IPO does not provide a dedicated DAS deposit form; the request is made through a written submission on the portal and processed manually by the Office.
In practice, IPO processing of DAS deposit requests usually takes several working days, so applicants should allow sufficient lead time before the intended PCT filing date. The request must be accompanied by the prescribed fee under Entry No. 49 of the First Schedule to the Patents Rules, 2003, and must include a valid email address. Once the certified copy is uploaded to WIPO DAS, the applicant receives a unique DAS access code by email.
When filing the PCT application at RO/IN using ePCT, the access code is entered on the Priority Claims screen under the option “International Bureau to obtain from a digital library (DAS)”. At this stage, ePCT performs real-time validation against the WIPO DAS database. If the IPO has not yet completed the upload of the certified copy, validation will fail and the DAS route cannot be used for the priority document. For this reason, the deposit request should be submitted well before the planned PCT filing date rather than on the filing day itself.
For paper PCT filings, the DAS access code is entered in Box No. VI of Form PCT/RO/101. A detailed walkthrough of the request form and ePCT filing process is available in our guide to filing a PCT international application from India.
Where the PCT application is filed at RO/IB, the applicant provides the DAS access code through ePCT or by written communication to the International Bureau. The deposit request itself may also be submitted after the PCT application has been filed, provided the access code is communicated to the IB before the date of international publication and the conditions of Rule 17.1(b-bis) are satisfied. These requirements remain subject to the general 16-month deadline from the priority date.
A practical advantage of WIPO DAS is that the same access code can be reused when the same Indian priority application is claimed in multiple later filings, including additional PCT applications or Paris Convention filings. A new deposit request is not required for each subsequent application.
Failing to furnish the priority document correctly can have serious consequences in PCT practice. If the priority document is not properly provided within the applicable deadlines, the priority claim may ultimately be disregarded by designated offices. For a broader discussion of priority-related risks, see our article on common PCT mistakes that can affect patent rights in India.
Finally, it is important to note that PCT Rule 17.1 and the WIPO DAS procedure described above apply only to patent priority documents for PCT international applications. Industrial design filings under the Hague System operate under a different procedural framework. For a broader understanding of how the international phase leads into national filings, see our guide to PCT national phase entry in India.
WIPO DAS India Fees: Priority Document Transmission Costs at the Indian Patent Office (2026)
When the Indian Patent Office (IPO) transmits a certified copy of a priority document through WIPO DAS, no transmission fee is charged to any applicant category. This applies equally to natural persons, startups, small entities, educational institutions, and large entities.
Where the priority document is furnished through the paper certified copy route, however, the IPO charges a transmission fee based on the applicant category and filing method.
It is important to distinguish between the DAS deposit request fee and the priority document transmission fee. The deposit request fee is payable when the applicant asks the IPO to upload a certified copy of the priority application to the WIPO DAS system under Entry No. 49 of the First Schedule to the Patents Rules, 2003. The transmission fee, by contrast, applies only when the Office transmits the certified copy to the International Bureau or another office.
The table below summarises the priority document transmission fees applicable at the Indian Patent Office as of 2026.
| Transmission method | Natural person / startup / small entity / educational institution | Others (large entity) |
|---|---|---|
| Online via WIPO DAS — up to 30 pages | None | None |
| Online via WIPO DAS — per page over 30 | None | None |
| Paper — electronic filing applicant, up to 30 pages | INR 1,000 | INR 5,000 |
| Paper — physical filing applicant, up to 30 pages | INR 1,100 | INR 5,500 |
| Paper — additional page fee (over 30 pages, electronic filer) | INR 30 | INR 150 |
Source: PCT Applicant’s Guide – India, Annex C (Receiving Office), effective 1 January 2026, published by World Intellectual Property Organization. The DAS deposit request fee under Entry No. 49 of the First Schedule to the Patents Rules, 2003 is not included in the table above.
In practice, because the WIPO DAS route eliminates transmission fees entirely, most applicants prefer depositing the priority document electronically rather than relying on the paper certified copy mechanism.
Priority Document Translations Under the 2024 Patent Amendment Rules
While WIPO DAS simplifies the availability and transmission of priority documents, it does not eliminate the requirement to provide a translation where the priority document is not in English.
Where the Controller invites the applicant to furnish a priority document translation, a verified English translation must be filed within the prescribed period. Under the Patents (Amendment) Rules, 2024, this deadline falls outside the condoning provisions of Rule 137.
If additional time is required, the applicant must request an extension under Rule 138. The extension fee is currently INR 10,000 per month for natural persons, startups, small entities, and educational institutions (electronic filing), and INR 50,000 per month for large entities (electronic filing).
For PCT applicants entering the Indian national phase, this issue often arises when the invitation to furnish the priority document coincides with the 31-month national phase timeline and the deadline for filing the Request for Examination (RFE). In such cases, applicants should ensure that the priority document translation is prepared in advance to avoid procedural delays.
For a detailed discussion of the procedural changes introduced by the 2024 amendments, see our article on the Patent Amendment Rules 2024.
No. Whether WIPO DAS is required depends primarily on the receiving office where the PCT application is filed.
An Indian applicant filing a PCT application at RO/IN may instead use the Rule 17.1(b) route, under which the Indian Patent Office prepares and transmits the certified copy of the priority document directly to the International Bureau upon request. In this situation, no DAS access code is required.
WIPO DAS becomes particularly relevant when the PCT application is filed at RO/IB or any receiving office other than the office of first filing, because the Rule 17.1(b) mechanism is unavailable in those cases.
Even when filing at RO/IN, many practitioners still request a DAS deposit. Once deposited, the same DAS access code can be reused if the same Indian priority application is later claimed in a Paris Convention filing or a subsequent PCT application, avoiding repeated certified copy requests.
The deposit request fee and the priority document transmission fee are separate charges.
The deposit request fee, payable under Entry No. 49 of the First Schedule to the Patents Rules, 2003, covers the Indian Patent Office’s processing of the applicant’s request to upload a certified copy of the priority application to the WIPO DAS system.
The transmission fee, by contrast, applies when the IPO transmits the certified copy to the International Bureau or another office. Where transmission occurs electronically through WIPO DAS, no transmission fee is charged for any applicant category. The fee applies only when the certified copy is transmitted through the paper route.
The outer legal limit is that the DAS access code must reach the International Bureau before the date of international publication, and the general 16-month deadline from the priority date under PCT Rule 17.1 must also be satisfied.
In practice, however, these outer limits should not be treated as safe targets. The Indian Patent Office processes DAS deposit requests manually, and ePCT validates the DAS access code in real time at the moment of PCT filing. If the IPO has not yet uploaded the certified copy, the validation will fail and the DAS route cannot be used.
For this reason, the safest practice is to submit the deposit request shortly after filing the Indian priority application, rather than waiting until the PCT filing deadline approaches.
Under PCT Rule 17.1(a), the certified copy of the priority document must reach the International Bureau within 16 months from the priority date.
If the document is not received by that date, the International Bureau notifies the applicant. A limited opportunity to correct the deficiency may exist in certain situations. However, if the certified copy is never furnished, the IB proceeds to publish the international application without the priority document, and designated offices may treat the priority claim as not having been made.
This can significantly affect the effective prior art date of the application in each designated jurisdiction.
Yes. Where the office of first filing has deposited the priority document in WIPO DAS, a foreign applicant entering the Indian national phase may provide the DAS access code when responding to the Controller’s invitation to furnish the priority document.
In that situation, the Indian Patent Office retrieves the certified copy electronically through WIPO DAS, rather than requiring the applicant to file a paper certified copy.
This depends on the office of first filing participating in WIPO DAS as a depositing office for the relevant document type, so it is advisable to confirm this before relying on the DAS route.
The Indian Patent Office processes DAS deposit requests manually, and no official processing timeline is published.
In practice, many practitioners report that access codes are issued within several working days after submission through the IPO e-filing portal, although processing times may vary depending on workload at the relevant patent office branch.
Because ePCT validates the access code in real time during PCT filing, an unprocessed deposit request can prevent the DAS route from being used on the filing date. As a result, the most reliable approach is to submit the DAS deposit request soon after filing the Indian priority application, rather than treating it as a last-minute pre-filing step.
How WIPO DAS Simplifies Priority Document Handling in India
WIPO DAS has become the standard mechanism for priority document exchange in international patent practice. Since the Indian Patent Office joined the system in January 2018, Indian applicants have been able to use the same electronic priority document workflow adopted by most major patent offices.
For an Indian applicant filing a PCT international application, the process is straightforward: request a DAS deposit through the IPO e-filing portal after filing the Indian priority application, enter the DAS access code during PCT filing in ePCT, and instruct the International Bureau to retrieve the document. Once retrieval is completed, the priority document requirement is satisfied electronically and no transmission fee applies.
For foreign counsel managing Indian priority chains, the IPO’s role as an accessing office means that paper certified copies of Indian priority applications are generally unnecessary where the document has been deposited in WIPO DAS. Whether managing outbound PCT filings or inbound national phase entries in India, the DAS system removes much of the administrative burden previously associated with priority document handling.
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Disclaimer:
This article is provided for general informational purposes and reflects the law and procedure as of March 2026. It does not constitute legal advice and should not be relied upon as a substitute for specific advice from a registered patent agent regarding the circumstances of a particular application