Short code vs long code
A district sending text messages sends them from a number, and there are three kinds of number to choose from. The choice determines what you pay, how fast a district-wide alert clears, whether families can reply, and — the part nobody mentions — whether you can take the number with you when you change vendors.
| Dedicated short code | Shared short code | 10DLC long code | Toll-free | |
|---|---|---|---|---|
| Example | 5 or 6 digits, yours alone | 5 or 6 digits, shared with other senders | Local 10-digit number | 800/833/844/855 etc. |
| Setup time | 8–12 weeks of carrier vetting | Faster, where still offered | Days to a few weeks | Days |
| Annual cost band | Thousands of dollars in lease fees alone | Lower, but declining availability | Low — per-number fees are nominal | Low |
| Throughput | Very high | High, shared | Moderate, trust-score dependent | High |
| Two-way replies | Yes | Yes, but routing is messy | Yes | Yes |
| Registration regime | Carrier programme brief | Programme brief | 10DLC brand + campaign | Toll-free verification |
| Portable to a new vendor | Yes, with a transfer process and time | No — it is not yours | Usually, if the district owns it | Usually |
Throughput is the reason short codes still exist
The technical case for a dedicated short code is one number: messages per second. When a district needs to reach 40,000 families in the first minutes of an incident, the constraint is not the platform — it is how quickly carriers will accept traffic from the originating number.
A 10DLC long code is throttled according to a trust score derived from the brand and campaign registration. For a registered district with a clean sending history, throughput is adequate for daily traffic and usually adequate for a closure notice. It is genuinely slower than a short code for a district-wide emergency send at the top of the size range, and any vendor who tells you otherwise is guessing.
The mitigations that matter more than the number type: sending across multiple numbers where the district has them, prioritising the fastest channel for emergency traffic, and failing over to voice on terminal SMS failure rather than recording a failure and stopping. Kastr does the failover part — a terminally failed SMS is retried as a voice call with the linkage recorded — and we do not publish a messages-per-second figure, because we have not run the load test that would justify one.
Cost, and the recognition trade-off
The commercial gap is stark. A dedicated short code carries a lease fee measured in thousands of dollars a year before a single message is sent, plus a vetting process measured in months. A 10DLC long code costs a nominal monthly fee per number and a registration process measured in weeks. For most districts under 15,000 students, the short code is difficult to justify on messaging volume alone.
What you buy with the premium is recognition. A short code that has been on the district's fridge magnets for six years is recognised instantly, and recognised senders get opened. That is a real effect and it is worth something.
The counter-effect is less discussed: a local long code gets called back. Families see a number with their own area code, and when a message says "contact the office", some of them simply hit dial. Whether that is an advantage depends entirely on whether the office is staffed to take those calls, which is a two-way communication question rather than a telecom one.
The practical split. Districts that can afford both often run a short code for district-wide emergency traffic and local long codes for school-level and classroom traffic. It costs more and it maps cleanly onto how families actually think about who is contacting them.
The portability question your incumbent would rather skip
Here is the procurement angle that almost never appears in a vendor's number-type explainer, because for most incumbents the answer is unflattering.
- A shared short code is not yours. It belongs to the vendor and is used by their other customers. If you leave, the number stays. Every fridge magnet, every enrolment packet and every "text JOIN to" instruction becomes wrong on cutover day.
- A dedicated short code can move, if the district is the registered lessee rather than the vendor. Check the lease documentation, not the vendor's assurance. Transfers take weeks and need co-operation from the party you are leaving.
- A 10DLC long code usually moves, if the district owns the number rather than borrowing it from the vendor's pool. Numbers from a vendor pool do not move, and pooled numbers are the default in most contracts.
Ask one question at renewal and at every RFP: which numbers do we own, and what is the documented process to take them to another provider? Get it in writing. A district that has printed one number on every school door for a decade has a switching cost that has nothing to do with software, and a vendor who benefits from that cost is unlikely to volunteer it.
Kastr's position: we treat number ownership as the district's, and our exit terms are contractual rather than aspirational — clause 7.1 covers export rights and clause 11.2 gives a 90-day exit with a prorated refund on a change of control or a material change to data terms.
Questions people actually ask
Can a district keep its short code if it changes vendors?
Only if the district is the registered lessee of a dedicated short code. A shared short code belongs to the vendor and cannot move. Check the lease paperwork rather than the sales assurance, and budget several weeks for a transfer that requires co-operation from the vendor you are leaving.
How much does a dedicated short code cost per year?
Lease fees alone run to thousands of dollars annually, before message costs, and carrier vetting takes roughly two to three months. For most districts the recognition benefit does not justify it against a registered 10DLC long code, which costs a nominal monthly fee.
Is a 10DLC long code fast enough for a district-wide alert?
For most districts, yes, provided the brand and campaign registration is complete and the sending history is clean. Throughput is trust-score dependent and is genuinely lower than a short code at the largest district sizes. Voice failover and channel prioritisation matter more than the raw number in practice.
Can parents reply to a short code?
Yes, short codes support two-way messaging. The harder question is routing: a reply has to reach a person who can answer it. On a shared short code, reply routing is messier because the number is not exclusively yours.
One price. Every feature. Locked for three years.
$3.50 per student per year under 5,000 students. No tiers, no add-on modules, no per-message fees. Published on the site because you should not have to book a call to learn a price.