If a company supplies the Greek state, there is a public record of it — and it is among the most concrete things you can read about a partner without asking anyone for anything.
What ΚΗΜΔΗΣ is
The Central Electronic Registry of Public Contracts records the acts in a public contract's life: the request, the notice, the contract and the payment orders. Each act gets its own ΑΔΑΜ, a permanent registration number.
What matters for checking a company: the contract record includes the supplier's details with their ΑΦΜ. No name-based matching is needed, which is always unreliable.
What you can read
Per company: how many contracts, with which contracting authorities, for what (via CPV codes), in which region, for how much and when. A supplier with a decade of contracts across many authorities is a different entity from one with a single contract last year.
What disclosed value does not mean
This is where the serious misreadings happen, and it is worth saying plainly.
A contract's value is not revenue. It is what the award states: it may never be drawn down in full. On a joint award with several suppliers, the same value appears for each of them, so per-supplier totals do not add up to the national total.
And amendments double-count if you are not careful: an amendment is recorded as a new act with its own ΑΔΑΜ and the whole value again, naming the act it replaces. Summing the raw rows inflates the total.
How to use it
As evidence of substance and specialism, not as a financial figure. A contract history shows the company genuinely operates, at what, and for whom. For its finances, read the annual statements published through ΓΕΜΗ — a different question and a different source.