Keep your T-Mobile number active while abroad

The American way of holding a number is a different instrument from anything in the Indian or Chinese systems. It is called a seasonal suspend, it lives inside your account, and its central fact is one that the coverage of it tends to bury: the bill does not stop.

What the suspend does and does not do

T-Mobile's support page is direct about the shape of it: "customers may request a seasonal suspend for up to 90 days per suspend period. Limited to 2 seasonal suspensions per rolling 12-month period." Two periods a year, ninety days each, is the outer edge of what the mechanism will do for a long absence.

The same page sets out what happens to the line: "when you suspend a line, all calls, text messages, voicemail, and data services are suspended. You'll keep your number and monthly plan". Keeping the number is the point. The line being dead to messages is the cost, and it matters if what you are holding the number for is verification codes rather than calls: the page says text messages are suspended, and it does not say a code waits until the line is restored.

The bill during a suspend

This is the part that gets summarized wrongly, usually as a token monthly fee. The support page says otherwise: "while a line is suspended, you're still responsible for paying your bill and if applicable, your monthly device payment and device protection charges. During the seasonal suspension, the full monthly recurring charges will be billed." The page carves out a single exception, the T-Mobile Internet AWAY plan at a $10 monthly recurring charge, which is a home internet product rather than a phone line.

So the arithmetic for a year abroad on a phone line is not a holding fee: each month inside a suspend period is billed at the plan's full monthly rate. Two periods of up to 90 days are about six months of that rate, plus whatever device installments are still running. A suspend does not cover the other half of the year. A suspend is a way to keep a number you are already paying for, not a way to stop paying.

If the line is prepaid

Prepaid accounts do not run on the seasonal suspend mechanism at all. T-Mobile's account suspensions page routes prepaid customers to a separate set of rules covering suspend and cancellation, and a prepaid line's survival depends on the balance and the inactivity terms of the plan rather than on a suspend request. If your T-Mobile line is prepaid, the seasonal suspend figures above do not describe your situation.

Before you fly

• Decide what the number is for. If it is for verification codes, a suspended line cannot receive them, so the suspend and the code-holding plan pull in opposite directions.
• Two suspends per rolling year means a stay longer than about six months needs a plan that does not depend on this mechanism.
• The full plan charge continues, so compare the cost against keeping the line active with a cheaper plan, or against porting the number to a service built for holding rather than for calling.
• What the other American networks do is on keep your US number while abroad, and the four routes in full are compared on hold, park, port or let go.