回程之前，有哪些事该收尾

There is no rush. A profile with its data switched off does not drain the battery or generate charges, and keeping it means that if you return to the same country you may be able to add a new plan to the existing profile rather than installing from scratch — though whether that is possible depends on the supplier's own terms. The one constraint is that each device holds a limited number of profiles; when you run out of room, remove the ones that are genuinely finished. Bear in mind that once deleted, a profile usually cannot be reinstalled from the original QR code, so check with the supplier before removing anything.

Travel data plans generally do not refund what you did not use, and the balance does not roll into the next plan. How much validity remains depends on the individual plan: some count from first activation, others from the date of purchase. If you are returning to the same country within that window, open the plan's details in your own account rather than working from a general rule, because the terms vary by supplier and by plan type.

Wait until you have landed back home. Switching while still abroad puts your main SIM onto roaming, billed according to your home operator's arrangements, which is probably not what you intended. Once you are home, do three things in one go: point the default data line back at the main SIM, turn its data on, and turn data off on the travel profile. Doing all three together avoids a gap where the phone cannot find a working connection at all.

Find any usable Wi-Fi first — the terminal network or a café inside it — then sign in to your account with the supplier and see whether you can add a plan to the profile already installed. Topping up an existing profile is usually faster than installing a new one, since it skips the installation step that needs a steady signal to complete. While you are at it, protect the battery: on a long unplanned wait, power tends to run out before data does.

It is still useful. The receipt or confirmation email is the record of what you bought, when, and from whom, which matters if you ever need to contact support afterwards. Read alongside how much data you actually used, it also tells you what size to buy next time. Saving the file into that trip's folder is enough; there is no need to print anything.

No: disabling is enough. Delete when it has genuinely expired, or when the device's profile slots are running out.

Check the home SIM is enabled and set as the data line again, then restart. Those two fix almost every case.