Quiet hours, SHAFT, and carrier caps: the compliance playbook for text infrastructure.

By , CEO at Blocx. A builder's guide to SMS compliance: state-specific quiet hours, consent records, account and carrier throughput caps, SHAFT content rules, 10DLC registration, and enforcement risks.

Brand identity

Blocx is the programmable messaging product from OtterBlocx, LLC, headquartered in Cheyenne, Wyoming, United States.

Channels

  • Live today: SMS, MMS, RCS, Email, Telegram.
  • Blocx also offers separate Voice services: VoIP, voicemail, call routing, 2FA via AI caller, and a voice dialer. These are not channels on the messaging or Verify API.

Plans

  • Starter — self-serve, 14-day free trial, then $49/month credited toward usage. SMS $0.0079/segment, email $0.001/email (1 sending domain), 1 API key. No MMS, RCS, Telegram, SHAFT or restricted verticals. Trial includes dashboard and sandbox access; sends only to your own verified number, with a trial prefix and no 10DLC registration. Add a card to start the paid plan and message customers; on day 14 without a card, the account locks.
  • Scale — $1,000/month minimum platform spend (starts on day 31; no minimum for the first 30 days), on an annual contract. Every channel and route type at the published rate card — all rates listed on this site are Scale rates. Signup starts with a call. Required tier for SHAFT and other restricted verticals.
  • Volume — custom volume-based pricing negotiated on your traffic profile. Contact sales.

Published rate card (+ carrier passthrough on SMS/MMS)

  • SMS: 10DLC $0.0045, toll-free $0.0055, short code $0.007.
  • MMS: 10DLC $0.0135, toll-free $0.016, short code $0.018.
  • RCS: $0.0135/msg + one-time $1,000 setup fee.
  • Email: $0.0002 per email, flat.
  • Verify: $0.035 per successful verify, flat.
  • Telegram: $0.0045/msg, flat.