That last point is the one that surprises people, so it is worth separating clearly from the rest. Short codes, long codes and toll-free numbers are all ways of addressing SMS and MMS. RCS is addressed by a verified agent, and the brand identity a short code was once a weak proxy for, "this is really us", is carried by the agent's verified name, logo and checkmark instead.
What a short code actually is
Short codes are 5 or 6 digits, leased rather than owned, and administered in the US through the Common Short Code Administration. Getting one live has never been a self-serve action: the code is leased, then provisioned carrier by carrier, and each carrier reviews the programme it will be used for. That approval step is why short-code launches have historically been measured in months rather than days.
They were designed for a specific problem. When a bank or a national retailer needed to send at very high throughput and wanted a memorable number for keyword opt-ins ("text JOIN to 12345"), a short code was the only route that carriers would allow at that volume.
Why most brands no longer need one
A2P 10DLC changed the economics. Since 10DLC gave standard 10-digit numbers a sanctioned, registered path for application-to-person messaging, the majority of programmes that would once have required a short code now run on a registered long code or a verified toll-free number. Both are faster to launch, cheaper to run, and no longer carry the deliverability penalty that unregistered long codes used to.
Short codes still have a place. Very high sustained throughput, certain regulated programmes, and established keyword campaigns with real brand equity in the number itself are all legitimate reasons to keep one. What has changed is that it is now a deliberate choice rather than the default.
How this works with RCS
An RCS message is not sent from a short code, a long code or a toll-free number. It is sent from an RCS agent that Google and the carriers have verified, and it arrives showing your brand name, logo and a verification checkmark. See what is a verified sender for how that identity is established.
Numbers still matter for the fallback leg. When a recipient cannot receive RCS, the same message is delivered as SMS or MMS, and that leg is sent from a real number which needs to be registered. So a typical SimplyRCS programme has a verified RCS agent for the RCS traffic and a registered 10DLC or toll-free number underneath it for fallback. If you already hold a short code, it can keep serving that fallback role.
Can I keep my short code if I switch providers?
Yes. A short code is leased to your business, not to your messaging provider, so changing providers does not mean giving it up. Moving it is a migration rather than a simple transfer: the new provider has to be provisioned on the code with each carrier, which takes coordination and is slower than moving a long code or a toll-free number. Porting a number to a new messaging provider covers how each number type moves and what has to be re-filed alongside it.
Where SimplyRCS sits
SimplyRCS supports short codes, toll-free and 10DLC long codes alongside verified RCS, and will port existing numbers of all three kinds. For most new programmes we will recommend a registered 10DLC or toll-free number for the fallback leg rather than a short code, because it launches sooner and costs less, and because the brand recognition a short code used to buy is now carried by the verified RCS agent.
- A short code is a 5 or 6 digit number leased through the Common Short Code Administration and provisioned carrier by carrier.
- 10DLC and verified toll-free numbers now cover most use cases short codes were created for, faster and at lower cost.
- RCS is addressed by a verified agent, not by any phone number; numbers are used for the SMS and MMS fallback leg.
- A short code is leased to your business, so it survives a change of provider, though migrating it is slower than moving a long code.
- Short codes remain a reasonable choice for very high throughput and for established keyword programmes.