Scope of this answer
This answer applies only to the unified electronic visa. A regular tourist, private, business, work or study visa can have a different supporting-document rule.
Official evidence
These are the official Russian MFA, KD MID or official mission sources attached to the published rule versions.
Unified electronic visa — official application portal
Ministry of Foreign Affairs of the Russian Federation · checked 5 Sept 2026
Single-entry e-Visa; 120-day validity; stay up to 30 days; application 86 to 4 days before entry; decision within no more than 4 calendar days.Open official source