DPMAObservations & Oppositions builder
Intervention
Section 59(2) PatGBeitritt
A way to join somebody else's pending German opposition as a full opponent after you have been sued on the patent. The declaration and its full reasons are due within three months of the action. Fee EUR 200.
At a glance
3 months from being sued
EUR 200 intervention fee, fee number 313 600 (checked 22 Sep 2026)
- Who can file
- A third party sued on the patent, a declaratory claimant after a demand to cease, or a preliminary-injunction respondent.
- Deadline
- Three months from service of the action, or from receipt of the injunction application at court, while the opposition is pending.
- Official fee
- EUR 200, fee number 313 600. Pay inside the intervention period; at the Federal Patent Court, with the filing.
- Anonymous
- No. Standing is proved by documents that name the intervener.
- Representation
- Only without a German domicile, seat or establishment (Section 25 PatG).
- Language
- German (Section 126 PatG). Foreign passages relied on get a German translation.
- How it is filed
- DPMA: post, fax or DPMAdirektPro with a qualified signature. Federal Patent Court: beA, eBO or EGVP, among others. Never email.
- Party status
- Full opponent with its own grounds. An own appeal only if declared before the appeal period ran out.
What it is
Intervention, in brief
Section 59(2) PatG lets a third party join a pending opposition after the nine-month period has closed, if it has been sued for infringement, has sued for a declaration of non-infringement after a demand to cease, or faces a preliminary-injunction application (BGH X ZB 3/15).
The intervener becomes an opponent with its own grounds and stays in if the original opposition is withdrawn. A late intervention cannot be cured and cannot revive ended proceedings. It shares a name with EPO intervention under Art. 105 EPC, but not its rules.
Grounds it can carry
- Lack of noveltySection 21(1) no. 1 with Section 3 PatG
- Lack of inventive stepSection 21(1) no. 1 with Section 4 PatG
- Excluded subject matter or no industrial applicationSection 21(1) no. 1 with Sections 1 to 2a, 5 PatG
- Insufficient disclosureSection 21(1) no. 2 PatG
- Usurpation, by the injured party onlySection 21(1) no. 3 PatG
- Added matterSection 21(1) no. 4 PatG
Use it when
- Somebody else's opposition against the German patent is still pending and the nine-month period has closed.
- You have been sued on the patent, or face a preliminary-injunction application, and three months have not passed.
Choose another route when
- The nine-month opposition period is still running: file your own opposition, same EUR 200, no proof of litigation. Opposition
- No opposition is pending, or all opposition proceedings have ended. Nullity action
- The patent is European or the opposition is at the EPO. Intervention of the assumed infringer
How IPtorch builds it
From search to filing, minus the signature.
The invalidity search runs on into this filing when it ends, with no second click. Three model families take turns, so a draft is never checked by the model that wrote it.
- 1SearchClaims split into limitations, thousands of candidates screened, at least 50 references read in full.Gemini models read and check
- 2Claim mapA verbatim quotation and its location behind every limitation.Every cell checkable
- 3DraftWrites the papers in the office's format and language.Claude Opus 5.5 (Anthropic)
- 4ReviewChecks each citation against its document and builds the forms.Sol 6 (OpenAI)
- 5AdjudicateHigh strength: a third family rules on every objection.Gemini 3.1 Pro (Google)
- 6FolderUnsigned PDFs, ready for a professional to review, sign and file.Nothing is filed
What the builder does for this filing
- It starts from an invalidity search with at least 50 references read in full, re-qualifies each under Sections 3 and 4 PatG, and reuses the German opposition drafting: feature analysis, Section 21(1) grounds, pinpointed evidence.
- It computes the three months from service of the action, or from receipt of the injunction application at court, never from the date on the pleading, and diaries the day it reached court as a safer date.
- It proves standing, pendency and that you are not already an opponent from documents, admissibility first, and applies no Art. 105 EPC rule.
- It refuses before any spend if the intervener's name and address are missing, and nothing is filed or paid.
In the folder
- Declaration of intervention with reasonsAdmissibility first: chronology, limb, proof, period, pendency
- Exhibit indexB standing proof, A document copies, V power, Z payment
- Copies of every cited documentWith labelled machine translations printed beside the original text
- Fee 313 600 payment dataForms A 9530 and A 9532, or transfer details
- Admissibility proof checklistInternal: served claim, proof of service, register extract
- Sworn declaration on servicePrepared and held in reserve in case the office asks
- Power of attorney and form A 9520 dataWhere a representative acts; A 9520 for natural persons
Builder strength
You choose how hard it is checked.
You pay for the tokens the sessions use, at the models' list prices plus a 30% fee, not for the time allowed. How pricing works
Low
- Opus 5.5 drafts the submission
- Sol 6 builds and checks the final forms
Medium
- Opus 5.5 drafts the submission
- Sol 6 reviews and rebuilds the content
- Opus 5.5 builds the filing folder
- Sol 6 checks the form
High
- Opus 5.5 drafts the submission
- Sol 6 runs a deep prior-art search
- Opus 5.5 rebuilds the submission against the evidence
- Sol 6 attacks it as an adversarial examiner
- Gemini 3.1 Pro adjudicates the objections
- Opus 5.5 applies the fixes and builds the filing folder
- Scripted checks of the filing folder
- Sol 6 audits the whole folder
- Convergence gate
If the gate fails, one repair round: opus 5.5 repairs what the gate found, sol 6 audits the repair, convergence gate, again.
What stays with you
You review, sign and file.
- Have litigation counsel supply the served statement of claim and the proof of service.
- Sign by hand or with a qualified electronic signature, or send through your own secure court route.
- Sign SEPA mandate A 9530 by hand and post the original to the DPMA.
- File inside the three months and pay EUR 200 under fee number 313 600.
Where these go wrong
What the builder guards against.
- Counting the three months from the date on the statement of claim instead of the date of service.
- Proving service with the envelope alone. In 2021 the office demanded a sworn declaration (Einhell); annex the served document and formal proof of service.
Start with the evidence.
Upload the patent or enter its number. The invalidity search charts every claim, and the builder takes it from there.
Start an invalidity searchFacts checked against the office's rules on 22 September 2026. IPtorch is not a law firm and this page is not legal advice. The builder's output is unsigned work product for a registered professional to review, sign and file; nothing is filed and no fee is paid for you. Confirm current requirements, fees and deadlines with the receiving office.