How Carrier Fees Affect Your Twilio SMS Costs

US carrier fees for A2P SMS have been added incrementally since 2021 and now represent a significant component of the total cost of business SMS sent through Twilio and all other US messaging platforms. These fees are imposed by AT&T, T-Mobile, and Verizon on all application-to-person messaging traffic as a condition of network access for registered A2P senders, and they are passed through to customers by Twilio as line items on the monthly invoice. Understanding what these fees cover, how they are calculated, and when they apply is essential for accurate SMS budgeting.

The A2P 10DLC Per-Message Surcharge

The primary carrier fee for A2P SMS in the US is a surcharge of $0.003 per outbound message segment applied to all traffic sent through 10DLC-registered long code numbers. This surcharge is not charged by Twilio as a margin item; it is a carrier pass-through cost that Twilio collects on behalf of AT&T, T-Mobile, and Verizon. At $0.003 per segment on top of Twilio's base rate of $0.0079, the effective outbound SMS cost is $0.0109, representing a 38 percent increase over the published base rate. The surcharge was introduced incrementally starting in 2021 and has been the source of significant cost surprises for businesses that budgeted based on pre-2021 SMS rates.

Toll-Free and Short Code Fee Structures

Toll-free verified SMS has a different carrier fee structure from 10DLC and does not carry the same $0.003 per-message surcharge. Verified toll-free senders are treated as a trusted category by carriers, and the fee structure for verified toll-free is lower than the A2P 10DLC surcharge. Unverified toll-free numbers, however, are subject to aggressive carrier filtering and may carry higher effective costs through failed delivery rather than explicit surcharges. Short codes have their own fee structure negotiated directly with carriers during the provisioning process, and their per-message carrier fees are typically lower than 10DLC surcharges because short codes are a premium, pre-approved channel that carriers treat as trusted by definition.

SHAFT Category Penalties

Content in the SHAFT categories, which stands for Sex, Hate, Alcohol, Firearms, and Tobacco, is subject to higher carrier scrutiny and in some cases higher per-message fees or complete filtering regardless of registration status. Cannabis content falls into this category for most carrier policies. Messages that touch SHAFT categories through ambiguous language, even when the business itself operates legally, face higher rejection rates and in some cases account-level restrictions if carriers flag the traffic. The financial impact of SHAFT-adjacent content is not always a direct fee; it can manifest as a delivery rate below 80 percent, which means you are paying for messages that are silently blocked and never delivered.

How Carrier Fees Appear on Your Invoice

Twilio itemises carrier surcharges as separate line items on your monthly invoice, labelled as carrier surcharges or regulatory fees depending on the product. The SMS line items typically show the base rate cost and the carrier surcharge as separate amounts, making it possible to see exactly how much of your SMS bill is Twilio's margin versus carrier pass-through costs. This transparency is useful for internal cost reporting, as the carrier fee component is non-negotiable and not subject to volume discounts in the same way the Twilio base rate can be. Businesses negotiating committed-use discounts with Twilio should understand that the carrier surcharge component will typically not be discounted as part of a volume agreement.

Conclusion

Carrier fees are a fixed cost of doing business with A2P SMS in the US and are not negotiable with Twilio, but understanding how they apply to your specific number types and volume helps you budget accurately and choose the right number type for each use case. Book a free cost review with our team and we will show you exactly what you are paying in carrier fees and whether a different compliance path would reduce that cost.