How do you check that there's no "own" contractor in the tender

Participation in tenders requires time (and often money for submitting an application), which means it must be saved.
The most obvious way is to check who has won such tenders from this contractor before. We do it this way:
- We take "Contour.Purchases".
- We look for the tender by name, then click "All purchases of the customer", there we enter either the subject or keywords ("Site", "Bitrix", etc.).
- Let's see if there's a mono contractor who wins everything.
Note that you will most likely have to subcontract the old contractor if you win. Otherwise, expect "unexpected" falls of the system you are going to serve, or the wrong sources, or whatever.