3HK Prepaid SIM Validity Extension Logic
3HK prepaid SIM cards have an annoying feature - they don’t simply extend the validity period based on your current remaining days. If your remaining validity period already exceeds the extension days, then the extension days will be ignored.
For example, if your current remaining validity is 100 days and you top up HK$20, your validity period won’t be extended by 30 days, but will remain at 100 days.
Let’s say I top up over two hundred HK dollars on July 1, 2025. It will remind me to top up in advance, for example, possibly on June 20, 2026.
If I then top up another two hundred plus HK dollars, the validity period will only extend to June 20, 2027, not July 1, 2027.
| Amount Range (HKD) | Extension Days |
|---|---|
| $20 - $49.9 | 30 days |
| $50 - $99.9 | 90 days |
| $100 - $199.9 | 180 days |
| $200 or above | 365 days |