Prepaid describes how you pay, not how good the network is. Some prepaid packs renew automatically from a balance. Some no-contract monthly subscriptions look like a conventional plan but do not commit you for two years. Compare the renewal rules rather than the label.
A year of service: a worked example
SoSIM’s published renewal tariff includes HK$48 for 30 days. Thirteen complete renewals cost HK$624 and cover 390 days, enough for a continuous 365-day period. A hypothetical HK$128 monthly contract plus HK$18 compulsory fee costs HK$1,752 for 12 months, but a 24-month agreement still commits you for a further year.
This does not make the two services equivalent: compare usable data, speed, voice, hotspot, roaming and support. The calculation shows what the extra service costs. If none of those extras solves a problem, a larger headline allowance is not a saving.
The differences that affect daily use
| Question | Why it matters |
|---|---|
| What happens when payment fails? | A prepaid renewal can fail for insufficient balance. A monthly contract may continue accumulating charges until properly ended. |
| Does the number outlive the pack? | SIM/account expiry and data-pack expiry may be separate. Buying a voice pack does not automatically prove the number is extended. |
| Will my watch or extra SIM still work? | Confirm support on the exact tariff before porting. A cheap phone SIM may not include the add-on your current account uses. |
Switching can erase the first year’s saving
Get the old provider’s settlement amount before you buy. OFCA’s contract advice is particularly relevant to remaining fees and promotions. If switching saves HK$80 a month but leaving now costs HK$800, ten months of savings merely recover the exit cost. Waiting until the commitment ends may be cheaper.