Capabilities of Long Code, Short Code, and Toll-Free Phone Numbers

This article explains the key differences between long code, toll-free, and short code phone numbers for SMS and MMS messaging in Canada and the US.

Capability Comparison

Capability	Long Code	Toll-Free	Short Code
Geographic coverage	Can send SMS to any country	Can send SMS to any country	Can only send SMS within the same country as the short code
Voice calls	Yes	Yes	No
SMS filtering	A2P traffic subject to carrier filtering; US requires A2P 10DLC registration	Must be verified before it can send SMS; unverified toll-free SMS is blocked by US and Canadian carriers	No filtering when compliant with approved use case from short code application
SMS throughput	1 segment/second (cannot be increased)	3 segments/second by default (can be increased — contact support)	100 segments/second by default (can be increased — contact support)
MMS capability	Yes	Yes	US only, with one-time enablement fee

Long code (10-digit numbers):

In the US, A2P 10DLC registration with The Campaign Registry (TCR) is required for business messaging. Unregistered A2P traffic is subject to filtering or blocking by US carriers.
Canadian carriers have not introduced A2P 10DLC requirements for long codes at this time.

Toll-free numbers:

A toll-free number must be verified before it can send SMS — carriers block texts from unverified toll-free numbers. Verification needs your business details, your use case with sample messages, and proof of how people opt in, and review can take up to about 5 business days.
Self-serve toll-free verification is not available in Switchboard yet. Contact SIPSTACK Support to ask about it.
Some message categories are not permitted on toll-free SMS. See Forbidden Message Categories.

Short codes:

To send short code SMS in both Canada and the US, you need two separate short codes — one per country.
Short codes are the best option for high-volume marketing or promotional messaging.