Open interim invoice or instalment claim: when part of a claim can be reviewed separately
Open interim invoice or instalment claim: when a clearly separated part of a claim can be reviewed separately.
31 July 2026, Mag. Bernhard Brandauer, Rechtsanwalt
An open interim invoice is not automatically the same as the whole contract. In ongoing services, a separated part of the claim may be reviewed where performance, period and amount are clearly distinguishable.
That separation can help where the entire relationship should not be escalated. It can also be risky if later objections, defect allegations or counterclaims affect the part claim.
This article is general information and does not replace advice on an individual case. It helps prepare the enquiry so the firm can distinguish review, letter, settlement, lawsuit or enforcement route.
Which review comes before the next step?
Answer one short question on the claim situation. The orientation does not replace legal advice, but helps prepare documents.
Already know you want to get in touch? Go straight to the enquiry form.
What matters most right now?
The next step depends on due date, evidence, objections and economic sense.
Overview of all answers.
Structure documents first
Start with a chronological file. Mark due date, open amount, previous payments and the last debtor reaction.
Take objections seriously
Where the claim is disputed, offset, defects or delay tactics must be reviewed before pressure is increased. The firm first checks which part of the claim is robust.
Review deadlines separately
For older claims, cross border facts or an existing title, state the relevant date and any urgency clearly.
Legal review frame
Austrian contract law on work, due date and partial performance, together with procedural requirements for a determinable money claim, forms the review frame. A partial claim needs clear separation.
The rules named here are review frames. They do not decide the case automatically. Contract, documents, debtor reaction and economic proportionality remain decisive.
If a deadline, cross border element or pending proceeding is involved, review should not be postponed through a general form alone.
Documents that now matter
Relevant documents include performance sections, acceptance or usability, interim invoice, payment schedule, time records, delivery notes and reactions to the exact item. The open balance should not be mixed with later work.
A concise chronological overview helps more than an unstructured document bundle. Open amount, partial payments and objections should be separated.
Please submit only key facts in the first form. Full files, sensitive debtor data and larger attachments should follow only through an approved firm channel.
Common mistake: A common mistake is to treat a part claim as isolated when it actually depends on the whole dispute. The apparently simple amount may then open the whole contract evidence issue.
How the firm reviews the next step
BRANDAUER Attorneys first review whether a mandate can be accepted and whether deadlines, conflicts of interest or economic limits must be considered.
The claim, evidence, objections and debtor data are then structured. Only that review shows whether a lawyer letter, lawsuit, settlement or enforcement step is sensible.
The firm reviews your information and agrees the next step with you personally. Sensitive documents should not be sent through public forms without prior arrangement.
Frequent questions
Can only an interim invoice be pursued?
That depends on whether the part claim can be separated legally and mathematically. The firm therefore first reviews performance, period, invoice and objections.
How should I communicate urgency?
No. The online enquiry structures the facts. State the relevant date and any urgency clearly.
Can the firm act against the debtor immediately?
After the conflict check and document review, the firm agrees the next step with you personally. Before that, the enquiry is only a first orientation.
Related pages
Interim invoice, Instalment, Work fee, Claim, Claim review, Austria, BRANDAUER