One code, or a line you hold
The two products answer different questions, and the deciding one is whether a second message will ever arrive.
These are not two prices for the same thing. A single activation ends when the code lands and the line rejoins the pool. A term keeps one line answering for as long as you hold it. The choice between them turns on one question, and it is not the price.
The question #
Will anything ever be sent to that number a second time? Not "might it be useful" — will it. A sign-in from an unfamiliar device, a password reset, a confirmation that turns up days after an order, a platform that re-verifies every few months. If any of those is on the cards, the line has to still exist when it happens, and a single activation will not.
Where one code genuinely is the whole story — a forum, a one-off download, something you will never sign into again — a term is time bought and left unused, at several times the cost.
Where the arithmetic crosses over #
Roughly two codes. Below that, single activations win comfortably. Above it, the term is already cheaper, and it has the advantage that no amount of paying more later can recreate a line that has gone back to the carrier.
What a term does and does not do #
Neither one sends. Both are inboxes rather than SIM cards, so a platform that wants to call you back cannot be completed on either.
If you already chose wrong #
Where a single activation was used and the platform now wants that number again, the line is gone and no support request retrieves it — it belongs to the carrier and has very likely been issued to somebody else. The repair is at the account level: a recovery address, an authenticator, anything that does not route through a number you do not own. Setting one at registration takes seconds and is worth doing on every account that matters, whichever product you chose.
If the first code never turns up, that is not the product being wrong: Nothing arrived. What now and Choose the country before the tariff.
