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Why does a multi-year certificate show a 1-year validity period?

Since September 1, 2020, all browsers only support SSL certificates with a maximum validity period of no more than 398 days. Certificates with a validity period exceeding this duration will be issued in multiple batches. This is a browser display rule that all certificate brands must comply with. This regulation, led by the CA/Browser Forum, aims to increase the update frequency of encryption algorithms and improve security.

Therefore, when a customer purchases an n-year certificate (n≥2), generally speaking, a 13-month certificate will be issued for the first (n-1) years, and a certificate covering the remaining validity period will be issued for the last year. The certificate for the next year will be reissued within 30 days before the current year's certificate expires. After receiving the new certificate each year, the customer only needs to deploy the new certificate to replace the old one before the original certificate expires.

Let's take the specific issuance timeline of multi-year certificates as an example:

  1. racent.com issued a two-year certificate on 2025.4.8:

    • Validity period for the first year: 2025.4.8 — 2026.5.8 (13 months issued for the first year)
    • Validity period for the second year: 2026.4.10 — 2027.4.8 (Assuming reissuance on 4.10, within 30 days before the first-year certificate expires, the remaining validity period is issued for the second year)
    • The total validity period of the certificate is two years: 2025.4.8 — 2027.4.8;

  2. racent.com issued a five-year certificate on 2020.7.4:

    • Validity period for the first year: 2020.7.4 — 2021.7.4 (13 months issued for the first year)
    • Validity period for the second year: 2021.6.6 — 2022.7.6 (Assuming reissuance on 6.6, 13 months issued for the second year)
    • Validity period for the third year: 2022.6.8 — 2023.7.8 (Assuming reissuance on 6.8, 13 months issued for the third year)
    • Validity period for the fourth year: 2023.6.10 — 2024.7.10 (Assuming reissuance on 6.10, 13 months issued for the fourth year)
    • Validity period for the fifth year: 2024.6.12 — 2025.7.4 (Assuming reissuance on 6.12, the remaining validity period is issued for the fifth year)
    • The total validity period of the certificate is five years: 2020.7.4 — 2025.7.4;

The above examples can roughly illustrate how the validity period of annually issued multi-year certificates is calculated. The specific validity period of the certificate issued each year is determined by the customer's operations.

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