How to port your mobile number in Hong Kong: steps and timeline

To keep your Hong Kong mobile number when you switch carriers, you apply to the new carrier — not the old one — and they run the port for you. The single rule that prevents a service gap: start the application a handful of days before your current contract expires, commonly about a week to ten days ahead, so the cut-over lands as the old contract ends. Apply too late and you risk a coverage gap; port out mid-contract and you risk an early-termination charge. Confirm the exact lead time with your carriers, as it can vary.

Before you start: what you need on hand

• Your existing mobile number and the account it sits on.
• The Hong Kong ID (or the identity document the account was opened with).
• Your current contract expiry date — this drives the whole timeline.
• The new plan you are moving to, chosen and confirmed.

The steps

Step 1 — Check your contract expiry. Find the exact end date of your current commitment. Everything below counts backwards from it. If you are still mid-contract, check the early-termination fee first — porting out early can trigger it. (Time: a few minutes.)

Step 2 — Pick the new plan and carrier. Decide what you are moving to before you apply, because the porting request goes to the new carrier. (Time: however long the decision takes — a Telecom Rex consultant can shortlist plans for your usage.)

Step 3 — Submit the porting request to the NEW carrier. Give them your existing number and ID; they handle the request to release it from your old carrier. Do not cancel with your old carrier yourself — doing that first can lose the number. (Time: the application itself is short.)

Step 4 — Wait for the port window. The number transfers during a scheduled cut-over, usually completed within a short window. Keep your old SIM active until it completes — service moves to the new SIM at cut-over. (Time: the new carrier will tell you the exact window.)

Step 5 — Confirm and finish. Once calls and data run on the new SIM, the port is done. Verify the old line has closed so you are not billed twice. (Time: a few minutes to check.)

Timeline at a glance

Count backwards from your contract expiry date (Day 0).

When	What happens
~ a week to ten days before expiry	Submit the porting request to the new carrier
Between then and expiry	Porting window processes; keep the old SIM active
Contract expiry (Day 0)	Cut-over to the new SIM as the old contract ends
Day 0 onward	Confirm service on the new SIM; check the old line is closed

Applying in this window is what avoids both a service gap (applying too late) and an overlap where you pay two carriers or trigger an early-termination fee (porting out mid-contract). Those are the two failure modes worth planning around.

Where Telecom Rex fits

Porting is mostly about timing, and the timing depends on your specific contract. A consultant on Telecom Rex (電訊暴龍) can check your expiry date, line up the new plan, and submit the request in the right window so you are not doing the countdown yourself. The point of 電訊暴龍 is that a verified person handles the switch rather than you guessing the dates.

FAQ

Do I contact my old carrier or the new one to port my number?

The new carrier. You submit the porting request to the carrier you are moving to, and they arrange to release the number from your current carrier. Do not cancel with your old carrier first — that can forfeit the number.

Will my phone lose service during the port?

It should not, if you apply in the right window and keep the old SIM active until cut-over. Service moves to the new SIM when the port completes. A gap usually only happens when the request is submitted too late relative to the expiry date.

When should I apply relative to my contract ending?

A few days before your contract expires — commonly about a week to ten days ahead — so the cut-over lands as the old contract ends. This avoids both a coverage gap and porting out early, which can trigger an early-termination fee. Confirm the exact recommended lead time for your carriers.

Does porting cost anything?

Any porting or administration charge depends on the carrier and your situation; the bigger cost to watch is an early-termination fee if you port out before your current contract ends. Check both before you apply.