Toll-Free vs Short Code
When 10DLC throughput or compliance constraints don't fit, the two alternative paths for high-volume A2P SMS in the US are toll-free numbers and short codes. Each has very different cost, throughput, and provisioning profiles.
Toll-free numbers
A 10-digit phone number with an 800, 833, 844, 855, 866, 877, or 888 prefix. Originally PSTN voice-only, now widely used for SMS by businesses that want a long number with messaging.
| Attribute | Toll-free | |---|---| | Setup fee | $0 | | Monthly lease | $2-$5 per number | | Verification fee | $0 | | Verification time | 1-3 weeks (TFV review) | | Throughput (MPS) | 3 MPS unverified, 3 MPS verified (carrier-dependent; some allow higher) | | Daily volume cap (verified) | 200K to 2M depending on carrier | | Compliance framework | Toll-Free Verification (TFV) via the Toll-Free Messaging Aggregator process | | Voice support | Yes (toll-free voice calling included) | | MMS support | Yes (must also be TFV-verified) |
Best for: mid-volume use cases (50K-1M msgs/day), brands that want voice + SMS on the same number, businesses willing to wait 1-3 weeks for verification.
Toll-Free Verification (TFV)
Before a toll-free number can send any meaningful volume, it must pass TFV through the Aggregator's verification queue. Required submissions:
- Business name, address, EIN
- Use case description
- Sample messages
- Opt-in URL and screenshot showing the form
- Opt-in confirmation message
- Privacy policy URL (must reference SMS opt-in)
- Terms and conditions URL
Unverified toll-free numbers are throttled to ~250 messages/day per carrier and may be blocked entirely on T-Mobile.
Short codes
A 5- or 6-digit phone number assigned by the CTIA-administered Common Short Code Administration (CSCA), specifically for high-volume A2P messaging. Examples: 12345, 87687, 90832.
| Attribute | Short code | |---|---| | Setup fee | $650-$1500 (one-time provisioning) | | Monthly lease | $500-$1500 (per code) | | Verification fee | Included in setup | | Verification time | 4-12 weeks | | Throughput (MPS) | 100+ MPS standard, can request higher | | Daily volume cap | Effectively unlimited at most carrier-imposed practical limits | | Compliance framework | CTIA Short Code Monitoring Handbook, carrier-by-carrier program brief | | Voice support | No (SMS/MMS only) | | MMS support | Yes |
Best for: high-volume marketing campaigns, alert systems, 2FA at massive scale (banks, large e-commerce), brands that need brand recall on the number ("text JOIN to 12345").
Two types of short codes
| Type | Code selection | Cost | Use | |---|---|---|---| | Random short code | Carrier assigns | $500/mo | Generic use, no vanity | | Vanity short code | Customer requests specific code (e.g., 88888) | $1500/mo | Brand recall, marketing recall |
Short code application process
- Choose use case and audience size — CTIA pre-qualifies based on volume.
- Submit program brief — describes the campaign, opt-in mechanism, sample messages, expected volume.
- Pay setup fee — non-refundable.
- Carrier review — each of the major US carriers (T-Mobile, AT&T, Verizon, US Cellular) reviews separately, takes 2-6 weeks each.
- Provisioning — once all carriers approve, the code is provisioned on the SMS network.
Total elapsed time: 4-12 weeks. Plan accordingly.
Side-by-side decision matrix
| Question | Choose toll-free | Choose short code | |---|---|---| | Volume per day | < 1M | > 1M | | Marketing? | Some, with TFV | Yes, high volume | | 2FA at massive scale? | Up to ~500K/day | Yes, unlimited practical | | Voice + SMS on same number | Yes | No | | Budget < $200/month | Yes | No | | Brand recall on the number | No | Yes | | Need fast provisioning (days, not weeks) | Yes | No | | Sensitive content (financial, healthcare) | Workable | Better trust signaling |
Compared to 10DLC
| Attribute | 10DLC | Toll-free | Short code | |---|---|---|---| | Lease | $1-$2/mo | $2-$5/mo | $500-$1500/mo | | Setup | $0 | $0 | $650-$1500 | | MPS (typical) | 1-75 | 3 | 100+ | | Provisioning | Days | 1-3 weeks | 4-12 weeks | | Voice | Yes | Yes | No | | Best for | SMB, 2FA, transactional | Mid-volume mixed-use | High-volume marketing |
SignalWire-specific notes
Toll-free on SignalWire
- Purchase via the portal or REST API like any other number.
- TFV submission is done through the SignalWire portal (Messaging → Toll-Free Verification).
- Approval status visible in the portal; webhook fires on status change.
Short code on SignalWire
- Short code provisioning is a managed service. Contact SignalWire enterprise sales to start the application.
- SignalWire handles the CTIA application, carrier brief submissions, and program management.
- Once provisioned, the short code appears in the portal alongside other numbers and uses the same Messaging API for sending.
Compliance differences
| Rule | 10DLC | Toll-free | Short code | |---|---|---|---| | Opt-in required | Yes | Yes | Yes, with explicit double opt-in for marketing | | STOP keyword respected | Yes | Yes | Yes (audited by CTIA monitors) | | HELP keyword response | Yes | Yes | Yes | | Use-case alignment | TCR campaign | TFV use case | CTIA program brief | | Audit frequency | Carrier-driven | Aggregator + carrier | CTIA quarterly monitoring | | Penalty for violation | Campaign suspension | Number deverification | Short code revocation |
Short codes are audited most strictly. CTIA monitors send test STOP messages and HELP messages periodically; failure to respond correctly results in formal audit notices.
Cost projection — annual
For 500K msgs/day for a year:
| Channel | Per-msg cost | Lease cost | Setup | Annual total | |---|---|---|---|---| | 10DLC Vetted (50 numbers) | $0.0079 | $1.50 × 50 × 12 = $900 | $4 | $1,441,304 | | Toll-free (5 numbers verified) | $0.0090 | $3 × 5 × 12 = $180 | $0 | $1,642,680 | | Short code (1 random) | $0.0049 | $500 × 12 = $6,000 | $650 | $900,150 |
At 500K/day, short code wins on per-message cost. At lower volumes, 10DLC wins on total cost because the lease overhead doesn't dominate.
Migration considerations
Switching from 10DLC to short code mid-campaign is disruptive: existing opt-ins are number-specific, so consent must be re-obtained. Plan migrations only when the volume justifies the cost and you can re-send an opt-in confirmation as part of the transition.
Switching from toll-free to short code is more common — typically when daily volume exceeds 1M and the lease+throughput math flips.
Related patterns
- A2P 10DLC campaign registry — 10DLC registration
- A2P 10DLC vetting and trust scoring — improving 10DLC throughput
- Toll-free and hosted messaging — toll-free deep dive
- SMS best practices — universal compliance rules
References
- CTIA Short Code Monitoring Handbook v1.7
- Toll-Free Number Administrator (Somos) — Toll-Free Verification process
- US Short Code Administration — Application and program management