SMS Opt-In Compliance Documentation

Last updated: August 2026  ·  Updraft Labs LLC

1. SMS Alert Program

LMKwhen sends automated weather alert text messages to subscribers who have opted in to receive notifications for their monitored locations. Alerts are triggered by active National Weather Service warnings and watches that intersect a subscriber's saved locations. Message frequency varies based on weather activity — subscribers in active severe weather regions may receive multiple messages during a weather event; subscribers in quiet periods may receive none.

2. Standard Messaging Keywords

3. Opt-In Flow 1: Guest Alert Opt-In (QR Code / Public URL)

Property managers and event organizers can generate a QR code that guests scan to opt in to temporary weather alerts. This flow requires no account creation. The subscriber enters their phone number on a public page and receives a confirmation SMS. Sessions expire automatically after a configurable duration (default 4 hours).

SMS consent is captured as a separate, affirmative act. The page presents a dedicated consent checkbox that is unchecked by default and carries the full disclosure in its own label. Consent is never inferred from entering a phone number or from pressing the submit button, and the box is never pre-selected on the subscriber's behalf. If the form is submitted with the box unticked, no number is enrolled and the page asks the subscriber to tick it. The page also states that consent is not a condition of using LMKwhen.

4. Opt-In Flow 2: Dashboard SMS Channel (Authenticated Users)

Registered LMKwhen users add SMS channels from the Delivery Channels page of their account dashboard. Adding a number does not by itself enable messaging to it. Every SMS channel goes through a mandatory second step in which the person who holds the handset confirms consent on a web page before any alert can be delivered (see Section 5). This flow requires an active LMKwhen account.

1. The account holder opens Delivery Channels → Add channel and selects the SMS tab.
2. They enter a label and a phone number in E.164 format. The consent disclosure is displayed directly above the submit button, before submission.
3. On submit, LMKwhen creates the channel in an unverified state and immediately sends a verification SMS to the number entered.
4. The channel remains dark — no alerts of any kind are delivered to it — until the recipient confirms on the consent page described in Section 5.

After the channel is created it appears in the Delivery Channels list carrying a verification-state badge. The badge reflects the current consent state of that specific handset, and an action button lets the account holder send or re-send the verification message. A channel only becomes eligible to receive alerts once its badge reads Verified.

The five badge states shown to the account holder are:

5. Confirmation Messages and Consent Capture

5.1  Guest flow confirmation

Sent immediately after opt-in via the guest flow described in Section 3. In that flow the subscriber enters their own number on the public page and ticks the dedicated consent checkbox; that tick is the consent event, and this message confirms enrollment:

Confirmation SMS sent to guest subscribers upon enrollment.

5.2  Dashboard flow: verification message and explicit web consent

The dashboard flow (Section 4) differs in one important respect: the account holder who enters the number is not necessarily the person who holds the handset. A property manager may add a maintenance supervisor's number, or an organization may add an on-call phone. LMKwhen therefore does not treat the account holder's action as consent. Instead it sends a verification message containing a temporary, single-use opt-in link, and the number is enrolled only when the person holding that handset opens the link and explicitly agrees on a web page.

The verification message is sent to the number as soon as the channel is created. It identifies the sender, states the purpose, carries STOP language, and contains the opt-in link. Three variants are used depending on who is adding the number:

Variant 1 — account holder adding their own number.

Variant 2 — an organization member adding someone else's number. The requesting person and the organization are both named so the recipient knows who is asking.

Variant 3 — organization-owned number where the requesting individual is not resolvable.

Links in the verification message are rewritten at send time to LMKwhen's own branded short domain, sms.lmkwhen.com, so the recipient sees a domain owned by the sender rather than a generic third-party shortener.

The opt-in link is a credential, not a page address. It carries a token with 256 bits of entropy, is valid for a single use, and expires 7 days after issue. Consent is recorded only in response to an explicit action taken on the page, never by the link being opened — the confirmation is submitted as a POST, so link scanners, spam filters, and message previews that fetch the URL cannot enroll a number. Requests to the consent endpoints are rate limited per source address.

Opening the link presents the consent page below. The recipient must tap Confirm. A Decline option of equal prominence is presented alongside it, and the page states that consent is not a condition of using the service:

Upon confirmation the recipient sees an acknowledgement that alerts will begin at that number. If they decline, the page confirms that no alerts will be sent, the token is permanently invalidated, and the account holder sees the channel marked Declined by recipient.

5.3  Server-side consent record

Every step of the exchange is written to LMKwhen's database at the moment it occurs and is retained as the record of consent for that specific handset. The record is keyed to the individual phone number, not to the account that entered it. The following are logged:

The consent record is enforced, not merely retained. LMKwhen's notification dispatcher filters out any SMS destination that does not carry a confirmation timestamp before messages are queued. A number that has not been confirmed, whose link expired, or that was declined cannot receive an alert — including life-safety alerts — regardless of the account holder's configuration. Re-sending a verification link invalidates all previously issued links for that number, and link issuance is capped at three per number per hour.

An opt-out received later by any route — a STOP reply to the carrier, or removal by the account holder — is recorded against the number and applied independently of the confirmation record above.

6. Sample Alert Messages

Alerts are sent only to numbers carrying a confirmed consent record. Every alert message carries STOP language.

Alert triggered by an active NWS Tornado Warning intersecting a monitored location.

All-clear message sent when the warning expires or is cancelled, if the subscriber's rule is configured to receive them.

7. Policies