A long code is a standard-length phone number, 10 digits in the US and Canada and a full national number elsewhere, that can make and receive calls and send and receive text messages. The name distinguishes it from a short code, the five- or six-digit numbers used for high-volume business texting. Long codes were designed for ordinary person-to-person (P2P) texting between phones, but businesses also use them for application-to-person (A2P) messaging, and in the US that business use is governed by the 10DLC registration framework.
At a glance
- A long code is a regular phone number, as opposed to a short code; toll-free numbers are a separate US category with their own texting rules.
- Long codes can usually carry both voice and texts, so customers can call and text the same number.
- They were built for P2P texting; business (A2P) use is treated differently by carriers.
- In the US, A2P texting from local long codes is expected to be registered under 10DLC.
- Outside the US, rules on business use of long codes vary by country; some prefer or require other sender types.
What problem it solves
Businesses want customers to reach them on one familiar number. A long code lets a store, clinic, branch or salesperson text and call from the same local-looking number, which recipients recognize and can reply to. That makes long codes the usual choice for conversational texting, appointment confirmations and customer service where replies matter.
The catch is that long codes were designed for people, not software. A phone sending a handful of personal texts looks very different from a platform sending thousands of messages, and carriers learned to treat high-volume traffic on long codes as suspect. Frameworks such as 10DLC exist so that businesses can keep using long codes for A2P messaging while carriers know who is sending and why.
How it works
Getting the number. Long codes come from your phone or messaging provider, either as new numbers or as existing numbers you port in. Not every voice number is text-enabled by default; texting may need to be switched on with a provider that supports it.
P2P use. Individuals texting from their mobile phones are P2P. Carriers expect low volumes, human pacing and replies in both directions.
A2P use in the US. When a business sends from a local long code through a cloud phone system, contact center or messaging platform, carriers generally treat it as A2P even when a person types each message. Your provider registers the business and its use cases with The Campaign Registry, links the numbers to campaigns once they are accepted, and carriers apply sending limits based on that registration.
Outside the US. Many countries allow business texting from long codes, sometimes called virtual mobile numbers, often for two-way messaging. Others restrict A2P on long codes, rewrite the sender or favor an alphanumeric sender ID. Requirements change, so check each destination with your provider.
Delivery. Traffic that looks unregistered, exceeds expected volumes or doesn’t match its declared use case is more likely to face carrier filtering.
If you’re adding texting to apps or workflows, our CPaaS solutions page explains how messaging providers compare.
When it matters for buyers
- Turning on texting in a cloud phone system or contact center using your existing local numbers.
- Deciding on sender types. Long codes suit conversational, local and moderate-volume traffic; short codes and toll-free numbers suit other patterns.
- Expanding internationally, where a US-style long code strategy may not carry over.
- Porting numbers between providers, where texting enablement and registrations need to move with the numbers.
Questions to ask vendors
- Are our numbers text-enabled on your platform, and can we keep our existing numbers?
- Do you handle 10DLC registration for our long codes, and how long does it usually take?
- What sending limits will our long codes have once registered?
- Which countries can we send to and receive from on long codes, and where do you recommend other sender types?
- How do you handle replies, opt-outs and help requests on long codes?
- If we port numbers away, does texting enablement move with them?
How it differs from 10DLC
A long code is a type of phone number; 10DLC is a US program for using local long codes for business texting. Every 10DLC number is a long code, but a long code used for personal texting, or one outside the US, is not part of 10DLC. When a US provider says “10DLC number,” it usually means a local long code that has been registered and linked to an approved business texting campaign. Long codes also carry voice calls and standard SMS and MMS; 10DLC governs how business text traffic on them is registered and treated.