The customer typically disputes the performance, does not recognise the additional work, or holds back part of the fee on the basis of faulty performance.
In these cases, documentation will decide. The construction log, the certificate of performance, the transfer-acquisition records, the written order of the additional work and the photo documentation together will prove the work carried out and its value.
The validation typically starts with the reconstructing of the settlement: what is the contract fee, what is covered by the subaccounts, and how much is disputed, followed by the request and the conciliation, and then, if necessary, the litigation procedure and implementation.
In the absence of a written contract, the claim may be enforceable if the order and delivery can be proved by other means.