Compare continuing cost over the same number of days
SoSIM’s official local tariff lists the existing-customer 60GB / 5,000-minute package at HK$48 for 30 days. Auto-renewal needs to be enabled and the account must hold enough balance. Twelve renewals cost HK$576 but cover 360 days, not a full 365-day year. The introductory HK$33 card is a separate first-purchase offer.
Birdie’s FAQ describes monthly billing with no binding contract and no administration charge. Use the price and allowance shown for your selected plan in the app, rather than an old price ladder. If you do not need service every month, work out whether ongoing billing or occasional prepaid purchases fit better.
The fallback speed changes what “unlimited” means
SoSIM’s standard local package runs at up to 42Mbps, falling to 128kbps after its fair-use allowance; included 5G passes are separate temporary benefits. Birdie’s FAQ lists different post-allowance limits by plan, including 128kbps, 2Mbps and 21Mbps. Check the exact subscription confirmation before relying on video calls or laptop tethering after the main allowance is used.
Stopping payment is not the same as managing the number
Birdie cancellation goes through its app, subject to the billing cutoff displayed there; email cancellation is not accepted. If porting out, keep the service active instead of cancelling it. With SoSIM, track SIM validity separately from the data-pack end date: stopping auto-renewal does not guarantee indefinite number retention.
Birdie
Consider Birdie when you want an ongoing monthly line and the chosen plan’s data and fallback speed justify its actual bill.
SoSIM
Consider SoSIM when its 30-day allowance fits your use and you are comfortable managing balance, renewals and the SIM expiry separately.
