The fee surfaces in two places, and neither is your rate card. An invoice carries it inside a total that exceeds rate times volume. Each message carries it as its own cost component, so a single send can be read back and attributed.
What is a carrier fee, exactly?
A charge from the network that accepted the message, reported separately from Bird's own.
A message's cost carries a transaction_amount, "What we charged to carry the message", and a passthrough_amount:
Third-party fees we pass on, as a decimal string, such as US 10DLC carrier surcharges.
A surcharge is neither a markup nor a tax. It moves independently of your rate, so a negotiated rate reduction leaves it where it was.
The fee attaches to the operator that terminates the message. It is therefore a property of the recipient's number rather than of your account.
Who levies them, and who collects them?
A mobile operator charges per message. A registry charges to register a sender.
The operator's charge applies to messages it accepts and delivers. Bird prices it against three dimensions: the operator a delivery receipt names, the destination country, and the sender type. The country decides whether a fee exists at all, since a combination the catalogue does not price is charged nothing rather than zero. Direction selects between two catalogue products, one outbound and one inbound, so a two-way programme can carry a fee on both.
The registry's charge is one-off and then periodic. In the United States that registry is The Campaign Registry, which states:
Currently, direct registration with TCR is not available for Brands. Instead, you must work with one of the registered messaging service providers (CSP) who will handle your registration process on your behalf.
Brand and campaign fees therefore appear on your provider's bill. The CTIA messaging principles covers why registration exists, and 10DLC registration covers the process.
Bird publishes both kinds on SMS carrier and 10DLC fees, priced from the billing catalogue. Which destinations carry a carrier fee, and what each one costs, are read live there.
When is the fee charged, and on what?
At delivery, per segment, and only when the delivery receipt names an operator.
Three consequences follow.
- A message never delivered carries no carrier fee. The charge follows the delivery receipt rather than the send. What is a delivery receipt covers when that arrives.
- Segments multiply the fee. It is charged once per segment, which makes encoding a billing question. What is an SMS segment and GSM-7 versus UCS-2 cover why one emoji can double the count.
- No operator named, no fee priced. The surcharge applies only where a delivery receipt carries an operator, which is why some traffic shows one and some does not.
Bird records the fee on the message. Read cost.passthrough_amount for the third party's charge and cost.transaction_amount for Bird's. The field separates two kinds of nothing: "0.00000" is an amount priced at zero, and null means no amount is recorded for that component.
How do I reduce what I pay in carrier fees?
Change the shape of the traffic. The per-message rate is set by the receiving network.
- Send fewer segments. The fee is counted per segment. Trimming a body under a segment boundary, or keeping it inside the GSM-7 alphabet, removes a whole multiple of the fee.
- Reconsider the sender type. The catalogue prices the fee per sender type, so the same message can carry a different surcharge from a long code, a toll-free number or a short code. Which sender type should I use covers the other trade-offs.
- Stop sending to recipients who cannot or should not receive. Suppressed recipients, stale numbers and retries all carry surcharge on top of rate.
- Register the sender. Unregistered traffic is filtered, and a filtered campaign still pays Bird's component on messages that never arrive.
The rate itself does not move. The levers a sender holds are how many messages go out, and how many segments each one takes.