The procedure for assigning an inventory number is contained in the Methodological Guidelines for Accounting for Fixed Assets. They say that the inventory number that is given to the asset object will be retained for it during the entire period of use of this object in the institution.
If the object and its parts have a common period of use, then they will be listed under one inventory number, etc.
When assigning an inventory number, take into account that when moving fixed assets within one legal entity, they must retain the inventory numbers assigned when accepting them for accounting, and also if the fixed assets arrived in the organization under a lease agreement, then these objects are accounted for by the inventory number that the landlord gave them.
Unlike the procedure for assigning inventory numbers, the procedure for compiling them is not described in any document on accounting for fixed assets. Therefore, organizations are required to independently compile the inventory numbers of fixed assets. It would be more correct if this is reflected in the accounting policy of the company or in a local act that will regulate the procedure for the formation of OS inventory numbers.
Each organization develops its own version of the inventory numbers. You can generate it according to the accounting number on which this asset is accounted for, or if there are branches, you can add a branch code. In the case of a small number of OS objects, numbers can be assigned in order, while it is desirable to keep a log of inventory numbers.