> ## Documentation Index > Fetch the complete documentation index at: https://www.vobiz.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # US SMS Regulations — TCPA, 10DLC, Quiet Hours & Opt-Out Rules > Regulatory requirements for sending SMS to US numbers on Vobiz — TCPA consent for text messages, A2P 10DLC campaign registration, quiet hours, opt-out handling, and how US SMS rules differ from India's DLT framework. ## Overview Sending SMS to US numbers requires compliance with two overlapping frameworks: **TCPA** (consent, opt-out, quiet hours) and **A2P 10DLC** (campaign registration with US carriers). Both apply regardless of where your business is located. > [!NOTE] > > For 10DLC brand and campaign registration on Vobiz, see [10DLC Brands](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-brands.md) and [10DLC Campaigns](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-campaigns.md). For the TCPA explainer see [What Is TCPA?](https://www.vobiz.ai/docs/blogs/what-is-tcpa.md). ## TCPA consent for SMS | SMS type | Consent required | | - | - | | Transactional (OTP, order confirmation, appointment reminder) | Prior express consent | | Marketing / promotional SMS | Prior express **written** consent | | Emergency / safety SMS | None | **Written consent for marketing SMS** requires a clear opt-in — a consumer actively agreeing to receive promotional messages from your business. Valid methods: * Web form opt-in with unchecked checkbox * Keyword opt-in (e.g., text JOIN to 56789) * Paper form with signature * Digital agreement with clear disclosure **What does not qualify**: Pre-checked opt-in boxes, consent bundled into terms of service without separate disclosure, or buying a contact list (the contacts never consented to hear from your company specifically). ## A2P 10DLC registration **10DLC (10-Digit Long Code)** is the US carrier framework for business SMS sent from standard 10-digit phone numbers. All A2P (application-to-person) SMS sent at scale to US numbers requires 10DLC registration. **Why it exists**: US carriers implemented 10DLC to combat SMS spam. Unregistered A2P traffic is filtered or blocked. Registered campaigns get higher throughput and better deliverability. **What you register:** | Component | What it is | Where | | - | - | - | | **Brand** | Your business entity — legal name, EIN, address | The Campaign Registry (TCR) via Vobiz | | **Campaign** | Use case for your messages — OTP, marketing, alerts | TCR via Vobiz | | **Numbers** | The 10-digit numbers you send from | Assigned to your campaign | **Registration steps on Vobiz:** 1. [Register your brand](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-brands.md) — business details, tax ID 2. [Create a campaign](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-campaigns.md) — select use case, provide message samples 3. Assign your Vobiz US numbers to the campaign 4. Carriers approve (typically 24–72 hours); throughput unlocked **10DLC throughput by use case:** | Use case | Messages per second (MPS) | | - | - | | OTP / 2FA | Up to 15 MPS | | Customer care | Up to 15 MPS | | Marketing | Up to 10 MPS | | Mixed / general | Up to 10 MPS | Unregistered long-code traffic is typically capped at 1 MPS and subject to filtering. ## Toll-free numbers — alternative to 10DLC US toll-free numbers (800, 888, 877, 866, 855, 844, 833) have their own verification process separate from 10DLC. Toll-free verification offers: * Higher throughput than unverified long code * National reach without per-state 10DLC complexity * Suitable for transactional and marketing use cases For toll-free SMS on Vobiz, see [US Toll-Free SMS](https://www.vobiz.ai/docs/sms/compliance/us-toll-free.md). ## Short codes — high-volume campaigns US short codes (5–6 digit numbers) are provisioned directly with carriers and offer the highest throughput (100+ MPS). They require a separate provisioning process (8–12 weeks) and monthly fees. Best suited for very high-volume campaigns (10M+ messages/month). ## Quiet hours for SMS TCPA quiet hours apply to SMS messages the same as voice calls: | Permitted hours | Zone | | - | - | | 8:00 AM – 9:00 PM | Recipient's local time zone | Sending marketing SMS outside these hours is a TCPA violation. Time zone determination must be based on the recipient's area code. ## Opt-out requirements US carriers enforce standard opt-out keywords automatically on 10DLC and toll-free traffic. You must also handle opt-outs at the application level: | Keyword | Action required | | - | - | | STOP, STOPALL, UNSUBSCRIBE, CANCEL, END, QUIT | Immediately stop all messages; confirm opt-out | | HELP, INFO | Respond with business name and opt-out instructions | | START, YES, UNSTOP | Re-subscribe if previously opted out | **Vobiz handles STOP responses automatically** — opted-out numbers are added to your suppression list and excluded from future campaign sends. **Re-engagement rule**: After an opt-out, you may send one confirmation SMS only. Any further messages require a new opt-in. ## US vs India SMS compliance — comparison | Dimension | US (TCPA + 10DLC) | India (TRAI + DLT) | | - | - | - | | **Framework** | TCPA (consent) + 10DLC (carrier registration) | TRAI TCCCPR + DLT platform | | **Campaign registration** | The Campaign Registry (TCR) | TRAI-authorised DLT operators | | **What's registered** | Brand entity + campaign use case | Entity + sender ID + each template | | **Template approval** | Use case category, not per-template | Per-template pre-approval | | **Consent for marketing** | Prior express written consent | DLT opt-in + DND scrub | | **DNC / suppression** | FTC National DNC Registry | NDNC registry | | **Quiet hours** | 8am–9pm recipient local time | 9am–9pm | | **Violations** | $500–$1,500 per message (private action) | Carrier-level blacklisting | ## Compliance checklist for US SMS on Vobiz * [ ] Obtain prior express written consent before any marketing SMS * [ ] Register brand and campaign on 10DLC before sending at scale * [ ] Assign sending numbers to your registered campaign * [ ] Include opt-out instructions in every marketing message ("Reply STOP to opt out") * [ ] Honour opt-out requests immediately — Vobiz handles STOP automatically * [ ] Restrict sends to 8am–9pm in the recipient's local time zone * [ ] Do not send to numbers on your internal suppression list * [ ] Scrub contacts against National DNC Registry for marketing campaigns * [ ] Review message content against CTIA messaging guidelines ## Related * [10DLC Brands](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-brands.md) — register your business entity * [10DLC Campaigns](https://www.vobiz.ai/docs/sms/compliance/us-10dlc-campaigns.md) — register your SMS use case * [US Toll-Free SMS](https://www.vobiz.ai/docs/sms/compliance/us-toll-free.md) — alternative to 10DLC for some use cases * [What is TCPA?](https://www.vobiz.ai/docs/blogs/what-is-tcpa.md) — full TCPA explainer * [US calling regulations](https://www.vobiz.ai/docs/compliance/us/calling-regulations.md) — TCPA for voice, STIR/SHAKEN, DNC * [India DLT registration](https://www.vobiz.ai/docs/best-practices/dlt-registration.md) — India SMS compliance * [Global compliance overview](https://www.vobiz.ai/docs/compliance/overview.md) — all markets at a glance This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.