A template is a message body registered ahead of time and sent by reference, with slots for the parts that change. It is the standard way to send transactional messages at volume, and the answer to whether it needs approving depends entirely on which channel you are asking about.
What is in a template?
A fixed body, typed variable slots, and a category. Bird's SMS templates guide describes it:
A template is a pre-registered message body you send by reference instead of inlining the text on every call. It carries its own category and typed variable slots, so a send supplies only values that change, such as a one-time passcode or order number.
Two things follow from sending by reference rather than by value.
The body is not composed at send time, so it cannot drift, and a message that has been reviewed stays the message that was reviewed. And the variables are typed, so a send that supplies the wrong shape fails at the call rather than producing a malformed message on a handset.
How is a template send different from a free-text send?
It fixes two things you would otherwise choose, and the guide is explicit about both:
Compared with a free-text send, a template send fixes the category and the sender. The template's category determines the per-country compliance classification. Bird selects the sender for the destination, so you don't pass
from.
That is more useful than it sounds. Picking a valid sender per destination is one of the genuinely fiddly parts of international SMS, since sender types are not carried everywhere. A template send takes that decision off you, which is why it is the easier path for anything going to more than one country.
The trade is that you lose control of both. If you need a specific sender, a free-text send is the way to keep it.
Do SMS templates need approval?
On Bird, no. Every SMS template in the catalog is already usable:
Status: the template's lifecycle state, rolled up across its languages. The field declares the same five states on every channel, so branch on it as an open set. Every SMS template reads Active today: at least one language is live, so the template can be sent. The other four (Draft, Pending, Rejected, and Inactive) are reachable only where you author template content and submit it for review, which SMS does not do, so no SMS template carries them today.
The reason no review step exists is that there is nothing to review: the catalog contains Bird's built-in system templates for common authentication and transactional messages, and workspace template authoring is unavailable. You are choosing from a set rather than submitting your own.
So a status field that looks like a review pipeline is one, just not for this channel. Note the distinction the guide draws, because it decides how you write code against it: the schema declares all five states for SMS, and only active is reachable today. Branch on the field as an open set rather than assuming one value.
Why do people expect approval then?
Because on other channels it genuinely exists, and the vocabulary is shared.
A WhatsApp template is submitted to Meta and reviewed before it can be sent, which is where most people meet the idea that a template needs approving. What is a WhatsApp message template covers that process. The same four statuses above exist for exactly that reason: they belong to channels where you author content and submit it.
Separately, SMS does have registration requirements in some markets, and those are easy to confuse with template approval. They are not the same thing. Registration concerns who is sending and is attached to the sender or the campaign; template approval concerns what the message says. A market can require the first and have nothing to say about the second. What is sender ID registration covers the sender side.
When should I use one?
Whenever the body is stable and the send is not.
Passcodes, order confirmations, delivery notifications and appointment reminders are all the same sentence with different values, which is exactly what a template is for. Free text suits the cases where the body is genuinely different each time, or where you need to control the sender yourself.
One practical note either way: templates do not change how a message is counted. A body plus substituted values is measured like any other, so a long value can push a message across a segment boundary for some recipients and not others. What is an SMS segment covers the counting.