While you are waiting for cooperation the client owes under the contract, it is the client, not you, who is in delay. The Commercial Code states expressly that a debtor is not in delay where it cannot perform as a result of the creditor's delay, and a client who fails to provide the necessary cooperation is a creditor in delay. If the client fails to provide that cooperation even within an additional reasonable period, you may withdraw from the contract and claim the price reduced by what you have saved. What matters, therefore, is whether the cooperation is identified in the contract and whether you are notifying its absence in a demonstrable way.
A software studio is to deliver a new module by an agreed date. For three weeks the client has not sent access rights to the test environment, has not approved the screen designs and has not responded to invitations to acceptance testing. Once the deadline has passed, however, an email arrives claiming a contractual penalty for delay. The Commercial Code (Act No. 513/1991 Coll.) caters for such a situation, but protects the supplier only to the extent that the client’s cooperation is genuinely its obligation.
An inactive client is in delay as creditor
Under a contract for work you are the debtor of the work and the client is the creditor. The law contemplates that a creditor, too, may be in delay:
A creditor is in delay where, contrary to its obligations arising from the obligation relationship, it fails to accept performance duly offered or fails to provide the cooperation necessary for the debtor to be able to discharge its obligation.
— Section 370 of Act No. 513/1991 Coll. (unofficial English translation)
The crucial words are “contrary to its obligations”. The duty to supply materials, to make an environment available, to decide on a design or to test a delivery must arise from the contract or its schedules. A contract which merely speaks of delivering software by a date leaves the supplier in a far weaker position than a contract with a timetable stating who is to deliver what and by when.
If the client is in delay, you are not. Under Section 365(4), a debtor is not in delay in so far as it cannot discharge its obligation as a result of the creditor’s delay. A penalty for the supplier’s delay therefore does not apply for that period, and the deadline moves by the time during which the missing cooperation prevented the work. In a dispute, however, you will have to show the connection: if you could meanwhile have continued on other parts and did not do so, the client’s inactivity will not entirely excuse you.
What the law gives the supplier
From a client in delay you may require performance of its obligation and damages under Section 373 et seq. (Section 371). You may withdraw from the contract in the cases provided for by law or by the contract (Section 371(2)), and the law expressly includes the creditor’s delay among them:
Where the delay of the debtor […] or of the creditor […] amounts to a material breach of its contractual obligation, the other party is entitled to withdraw from the contract if it notifies the party in delay without undue delay after learning of that breach.
— Section 345(1) of Act No. 513/1991 Coll. (unofficial English translation)
A breach is material where, already at the conclusion of the contract, it was reasonable to foresee that the other party would have no interest in performance if it occurred; in case of doubt, a breach is presumed not to be material (Section 345(2)). With late access rights or tests, this is hard to establish. If the breach is not material, you may withdraw once the client fails to provide the cooperation even within an additional reasonable period granted to it for that purpose (Section 346(1)). A written demand stating a specific period is therefore the foundation of the entire procedure.
Damages may include, for example, the cost of a team which waited for access rights, if you can evidence it. If you withdraw from the contract because of the customer’s delay and the impediment on its side does not consist in circumstances excluding liability, Section 548(2) entitles you to the price to which you are entitled under the contract, reduced by what you have saved by not executing the work in full.
Where the contract is governed by Czech law
The Czech Civil Code has a specific rule on cooperation in contracts for work. Under Section 2591, the contractor sets the customer a reasonable period for cooperation. Once it has expired fruitlessly, the contractor may procure substitute performance at the customer’s expense or, if it has warned the customer of this, withdraw from the contract. The warning is therefore a condition of withdrawal under that provision and belongs in the demand itself.
What to do at once and what belongs in the contract
Notify every instance of missing cooperation in writing, by email or in a ticket: what is missing, since when, what it affects and by how much the deadline moves. Continue with work which does not depend on the client and propose a revised timetable. If the client does not respond to acceptance testing either, an agreed deemed-acceptance mechanism helps; why silence on acceptance is dangerous even without one is explained in the question on an unsigned acceptance protocol and the price of the work.
The contract should contain a list of cooperation items with deadlines, a rule on the automatic postponement of deadlines, payment for standby time, and a right to withdraw after a fruitless demand with an additional period. How to set this up for sprints is discussed in the article on agile software development and the contract. We prepare or review contracts for IT work and agile development for suppliers and customers alike; for classic fixed-scope deliveries we use the general contract for work.
This answer provides general information on the law as at 12 September 2026. It does not constitute legal services or replace an assessment of an individual case. The details of your situation may differ. Book a consultation to discuss them.
