According to Beglov, during the partial mobilization last autumn, significant discrepancies were revealed in the systems for storing personal data of those liable for military service.
He noted that not all those liable for military service reported changes in marital status, education, change of residence or work.
The governor said "all these gaps" need to be addressed.
"Now in St. Petersburg, the process of clarifying the personal data of those liable for military service has begun," TASS quoted him as saying.
Earlier, the military commissar of the Yaroslavl region, Igor Gostev, said that summonses were planned to be sent to clarify the data of military registration.
Prior to this, the press Secretary of the President of Russia Dmitry Peskov said that the Kremlin does not discuss the possibility of announcing a new wave of mobilization.
He noted that the delivery of subpoenas to citizens to clarify the data is a common practice.