Cross check with your contragents. For every bit of incoming VAT should be outgoing VAT from your supplier. And for outgoing VAT should be incoming VAT for your client and/or sale to physical customer.

If your incoming VAT are not matched with outgoing VAT from your supplier, you will be charged.

If your supplier declared VAT, but failed to pay it, you have choice: either you have to pay it or you will be inspected to proof that it was not a fake.

Every sale to physical customer in Russia should be uploaded to tax service cloud. You (as a customer) could check your receipt online or using app, and get a reward for reporting tax evasion.

This system boosted VAT revenue x1.5 in a few years.