Dynamics of trade turnover often leads to a number of commercial transactions for which the law does not require a written or other qualified form getting concluded without being objectified in a written contract between the parties – deliveries are ordered with "a verbal agreement", goods or services are agreed on over the phone or by using modern electronic technologies. This, of course, in no way compromises the validity of the informal contract and its legal force binding the parties to it.
When it comes, however, to a dispute between the parties to such an agreement, provided that its price exceeds 5000 BGN, the reasonable question arises about proving the contractual relationship and the therefrom deriving rights and duties before court.
Indeed, the invoice VAT-registered traders issue for the number of goods/services they sell is a tax-accounting document which in itself does not prove the existence of a legal relationship and obligations arising from it.
The compulsory case law of the Supreme court under art. 290 of the Civil Procedural Code, however, clearly states that an invoice reflected in the accounting of the defendant company in a legal dispute, which is included within the VAT purchase and sales records of the defendant and defendant having used the tax credit for the same are clearly recognition of the liability and prove its existence. Particularly for contract of sale, the court holds that the invoice can be considered as evidence establishing a sales contract because the law does not require a special written agreement for the sale of movables, but the invoice must contain all the necessary elements qualifying the sales contract as such - the type of goods purchased, amount, method of payment, the names of persons Signatory as a recipient and transmitter, respectively, time and place. As for the servicing contracts, which is the type of contracts for construction works and a number of other service contracts, the court holds that the job done by the assignee and accepted by the assignor, which in turn is necessary for the emergence and collectibility of the obligation to pay reward under the contract, could be proved by the very fact of the issuance of invoice by the assignee and its being signed by the assignee and the assignor.
With its mandatory case law regarding the probative value of the invoice and its accounting the Supreme court greatly expands the importance of this tax accounting document thus helping merchants prove their claims against their defaulting contractors in a court.