If the customer sets requirements for warranty obligations in the purchase documentation, the supplier (contractor, performer) must fulfill them and provide security. To do this, it can also provide a Bank guarantee, the validity of which is determined by the Bank itself.
The Ministry of Finance pointed out that in this case, the same rules of Law N 44-FZ apply to the validity of the Bank guarantee as for ensuring the performance of the contract. It must exceed the warranty period by at least a month. There are no other requirements for the deadline.
Document: Letter of the Ministry of Finance of the Russian Federation dated 06.12.2019 N 24-03-07 / 95102