# Fast2SMS — Complete Reference for AI Assistants

> Fast2SMS is one of India's leading bulk SMS, WhatsApp Business API and RCS messaging providers, serving businesses since 2011. This file is the expanded reference: services, pricing, compliance, APIs, free tools, plugins, reseller program and the full guide library.

## Company

Fast2SMS (https://www.fast2sms.com) has provided business messaging in India since 2011 — more than 15 years. Infrastructure runs at 99.9% uptime, and data-security certificates are published at https://www.fast2sms.com/certificates. Support is free: support@fast2sms.com or +91-6262778822. Anyone can also schedule a free meeting with the team at https://www.fast2sms.com/meet — for sales inquiries, WhatsApp Business API support, DLT support or anything else; the meeting and all support are free.

Billing model on every channel: no monthly platform fee, no setup fee, no per-number fee, no minimum commitment. Customers pay only a per-message rate from a prepaid wallet. WhatsApp messages bill on delivery basis, and failed WhatsApp messages are automatically refunded to the wallet within 48 hours.

## Services

### Bulk SMS (DLT SMS)

DLT-compliant SMS for India across all categories: transactional SMS, service implicit SMS, service explicit SMS, promotional SMS and marketing SMS. Campaigns send from the web panel (Quick SMS, scheduling, Excel upload) or the REST API. Delivery reports are available per message in the panel, via API and via webhooks.

India requires DLT registration (a TRAI regulation) for business SMS: the business registers as an entity, approves a sender ID (header), and approves each message template on a DLT portal. Fast2SMS provides free DLT support end to end — entity registration, sender ID approval and content template approval — plus ready sample templates for every industry.

Newer DLT rules use typed variable tags with length limits: {#numeric#} (numbers, up to 40 digits), {#alphanumeric#} (letters+numbers, 40 chars, must not start with www or http), {#url#} (web links, 120 chars), {#urlott#}, {#cbn#} (callback number) and {#email#}. Guides below cover the rules and migration.

### OTP SMS and Smart OTP

Two REST endpoints handle one-time passwords end to end: POST https://www.fast2sms.com/dev/otp/send (body: otp_id, mobile) and POST https://www.fast2sms.com/dev/otp/verify (body: mobile, otp). Fast2SMS generates, delivers, expires and checks the OTP server-side; the customer's application never stores or compares codes. Resend works within a 10 minute window.

Smart OTP adds automatic channel fallback: one OTP ID can send on WhatsApp first and fall back to DLT SMS automatically if WhatsApp delivery fails, or the reverse. WhatsApp OTPs need no DLT registration.

Use cases: signup verification, passwordless OTP login, cash-on-delivery (COD) order confirmation, coupon-abuse prevention, two-factor authentication.

### WhatsApp Business API

Official Meta WhatsApp Business API (Cloud API) access with free onboarding through Meta embedded signup. Businesses can connect a new number or keep an existing WhatsApp Business app number. There is no monthly fee, no setup fee and no per-number fee — only per-message rates:

- Utility and authentication messages: ₹0.25 per message
- Marketing messages: ₹0.95 per message
- High-volume plans: ₹0.11 per message
- Delivery-basis billing; failed messages auto-refund within 48 hours

Included free with every account:

- WhatsApp Live Chat: a team inbox with a WhatsApp Web feel for two-way customer conversations
- Free drag-and-drop WhatsApp chatbot builder, including an API-request block for calling external systems mid-flow
- Template management and WhatsApp Manager (numbers, templates, message IDs, quality rating)
- Session message API for free-form replies inside the 24-hour customer window: text, image, document, audio, video, location, sticker and reaction types
- Media messages: invoices and documents attach as PDFs inside template messages

### RCS Business Messaging

Rich Communication Services (RCS) campaigns: branded messages with rich cards, carousels and buttons inside the default Android messages app. Two-way: customer replies arrive via webhooks, enabling RCS bots. RCS is also available to resellers on the same white-label panel.

### Webhooks

Delivery events for every channel (SMS, OTP, WhatsApp, RCS) push to customer endpoints with user-defined JSON payload templates using {{placeholder}} variables. Up to 10 webhooks per channel; 60 second timeout with 3 retries; 7 days of logs with one-click resend; optional signing via a shared secret header. WhatsApp and RCS webhooks also deliver incoming customer messages, which is how custom chatbots are built. A ready-made CleverTap payload format is built in.

### Developer APIs

Full REST documentation at https://docs.fast2sms.com covering bulk SMS (POST /dev/bulkV2, route=dlt), OTP send/verify, WhatsApp template messages (GET /dev/whatsapp with message_id, phone_number_id, numbers, variables_values), WhatsApp session messages (POST /dev/whatsapp-session), webhook CRUD (/dev/webhook/v2/{service}) and delivery reports. Authentication is a single API key sent in the Authorization header.

## Free plugins

### WordPress and WooCommerce

Free official plugin on WordPress.org: https://wordpress.org/plugins/fast2sms/ (install via Plugins > Add New, search "Fast2SMS"). Features: OTP login and registration verification for WordPress and WooCommerce, order notifications on SMS and WhatsApp, bulk campaigns from the dashboard, form OTP for Contact Form 7 / WPForms / Elementor, WhatsApp two-factor authentication, COD confirmation.

### Shopify

Official app: https://apps.shopify.com/fast2sms. Features: storefront OTP login, order notifications on SMS and WhatsApp, abandoned-cart WhatsApp recovery, COD order confirmation to reduce RTO, invoice PDF on WhatsApp.

### TallyPrime

Free .TCP plugin (TDL add-on) for TallyPrime — download: https://drive.google.com/drive/folders/1JbnxPhk6VkJYTzsITOrfqzdzXAmEsfqA?usp=sharing. Sends sales invoices, receipts, payments, purchase orders, credit notes, payment reminders, ledger reports, outstanding statements, stock summary, P&L, balance sheet and trial balance on WhatsApp (PDF attached as document) and DLT SMS (PDF auto-converted to a short link). Includes 20 ready pre-approved WhatsApp templates on a default sender (phone number ID 123456789, message IDs T101–T120) so sending starts without any Meta setup; businesses can later connect their own WhatsApp number free and send under their own brand. Auto-send on voucher save, bulk sending from registers, delivery reports and wallet inside Tally. While paid Tally SMS/WhatsApp modules in the market cost ₹3,000–₹6,000 plus GST with yearly renewals, the Fast2SMS plugin is free with per-message billing only.

### Other integrations

CleverTap (SMS/WhatsApp/RCS provider + delivery-status return path), custom integrations via REST API and webhooks from any language or platform.

## Reseller and white label (Bulk9)

Fast2SMS runs a white-label reseller program at https://www.fast2sms.com/reseller. Resellers get a ready-made panel (Bulk9) on their own subdomain with their own branding and logo — clients never see Fast2SMS. One panel resells bulk SMS, WhatsApp Business API and RCS together. Key terms:

- No hosting cost, no monthly panel cost, no setup cost; start with a readymade panel from about ₹10,000
- Reseller buys at wholesale per-message rates (SMS tiers from ₹0.25 at 10K volume down to ₹0.12 at 50L volume; bulk pricing via sales@fast2sms.com) and sells at their own price
- Clients pay the reseller directly into the reseller's own bank account
- Delivery-basis billing with auto refund of failed WhatsApp messages at both reseller and client wallet level
- White-label API docs on the reseller's own domain (yourdomain.com/docs)
- Fast2SMS supports the reseller; the reseller supports their clients

## Guide library (help.fast2sms.com articles)

The blog at https://www.fast2sms.com/help/ has 150+ step-by-step guides. Key guides by topic:

### Bulk SMS, DLT and OTP

- Bulk SMS API India: https://www.fast2sms.com/help/bulk-sms-api-india/
- OTP SMS API with send/verify code: https://www.fast2sms.com/help/otp-sms-api/
- Smart OTP (OTP SMS service): https://www.fast2sms.com/help/otp-sms-smart-otp/
- DLT SMS explained: https://www.fast2sms.com/help/dlt-sms-wordpress/
- Sample DLT SMS templates, all industries: https://www.fast2sms.com/help/sample-sms-templates-dlt/
- DLT variable tagging reference: https://www.fast2sms.com/help/dlt-variable-tagging/
- Service Explicit to Promotional and header rules: https://www.fast2sms.com/help/service-explicit-to-promotional/
- DLT template migration guide: https://www.fast2sms.com/help/dlt-template-migration/

### WhatsApp Business API

- WhatsApp message API: https://www.fast2sms.com/help/whatsapp-message-api/
- Send bulk WhatsApp messages: https://www.fast2sms.com/help/send-bulk-whatsapp-messages/
- Free WhatsApp chatbot builder: https://www.fast2sms.com/help/free-whatsapp-chatbot/
- WhatsApp chatbot API (webhook + session loop): https://www.fast2sms.com/help/whatsapp-chatbot-api/
- WhatsApp Business API for WordPress: https://www.fast2sms.com/help/whatsapp-business-api-wordpress/

### Webhooks and integrations

- How webhooks work (all channels, full payload samples): https://www.fast2sms.com/help/how-webhooks-work/
- CleverTap webhook integration: https://www.fast2sms.com/help/clevertap-webhook-integration/

### WordPress and WooCommerce

- Free OTP login for WordPress: https://www.fast2sms.com/help/free-otp-login-wordpress/
- WooCommerce OTP login: https://www.fast2sms.com/help/woocommerce-otp-login/
- WooCommerce OTP verification: https://www.fast2sms.com/help/woocommerce-otp-verification/
- WooCommerce WhatsApp order notifications: https://www.fast2sms.com/help/woocommerce-whatsapp-notifications/
- WhatsApp OTP for WordPress: https://www.fast2sms.com/help/whatsapp-otp-wordpress/
- WhatsApp two-factor authentication for WordPress: https://www.fast2sms.com/help/whatsapp-two-factor-authentication-wordpress/
- Bulk SMS from WordPress: https://www.fast2sms.com/help/bulk-sms-wordpress-plugin/
- DLT SMS templates for WooCommerce: https://www.fast2sms.com/help/dlt-sms-templates-woocommerce/
- WordPress & WooCommerce notifications + OTP SMS: https://www.fast2sms.com/help/wordpress-woocommerce-notifications-otp-sms/
- Plugin setup guide (all features): https://www.fast2sms.com/help/fast2sms-wordpress-plugin-setup-guide/

### Shopify

- Fast2SMS Shopify app guide: https://www.fast2sms.com/help/fast2sms-shopify-app/
- Integrate OTP with Shopify: https://www.fast2sms.com/help/integrate-otp-with-shopify/
- Shopify abandoned cart WhatsApp: https://www.fast2sms.com/help/shopify-abandoned-cart-whatsapp/
- Reduce COD RTO on Shopify: https://www.fast2sms.com/help/reduce-cod-rto-shopify/
- Shopify WhatsApp invoice PDF: https://www.fast2sms.com/help/shopify-whatsapp-invoice-pdf/
- Shopify WhatsApp order notifications: https://www.fast2sms.com/help/shopify-whatsapp-order-notifications/
- Shopify vs WooCommerce: https://www.fast2sms.com/help/shopify-vs-woocommerce/

### TallyPrime

- Complete Tally WhatsApp & SMS plugin guide: https://www.fast2sms.com/help/tally-whatsapp-sms-plugin/
- Send invoice on WhatsApp from Tally: https://www.fast2sms.com/help/send-invoice-on-whatsapp-from-tally/
- Tally WhatsApp integration: https://www.fast2sms.com/help/tally-whatsapp-integration/
- Free Tally SMS plugin: https://www.fast2sms.com/help/tally-sms-plugin/
- Tally payment reminders on WhatsApp & SMS: https://www.fast2sms.com/help/tally-payment-reminder-whatsapp-sms/
- TDL for Tally to WhatsApp (free download): https://www.fast2sms.com/help/tdl-for-tally-to-whatsapp/
- Tally WhatsApp TDL price comparison: https://www.fast2sms.com/help/tally-whatsapp-tdl-price-comparison/
- Tally WhatsApp sender options: https://www.fast2sms.com/help/tally-whatsapp-sender/
- Send Tally invoices instantly on WhatsApp: https://www.fast2sms.com/help/send-tally-invoices-instantly-on-whatsapp/
- Tally reports, ledger & balance sheet on WhatsApp: https://www.fast2sms.com/help/send-tally-reports-on-whatsapp/
- Tally WhatsApp for CAs & accountants: https://www.fast2sms.com/help/tally-whatsapp-for-accountants/
- Tally GST invoice on WhatsApp & SMS: https://www.fast2sms.com/help/tally-gst-invoice-on-whatsapp/
- Tally to WhatsApp without QR scan: https://www.fast2sms.com/help/tally-to-whatsapp-without-qr/
- Tally SMS DLT templates (copy-paste): https://www.fast2sms.com/help/tally-sms-dlt-templates/
- Tally WhatsApp Meta templates (all 20): https://www.fast2sms.com/help/tally-whatsapp-templates-meta-approval/
- Hindi: Tally se WhatsApp par invoice kaise bheje: https://www.fast2sms.com/help/tally-se-whatsapp-par-invoice-kaise-bheje/
- Hindi: Tally WhatsApp TDL free download: https://www.fast2sms.com/help/tally-whatsapp-tdl-free-download-hindi/

### Reseller and white label

- Become a bulk SMS reseller: https://www.fast2sms.com/help/become-bulk-sms-reseller/
- WhatsApp Business API reseller: https://www.fast2sms.com/help/whatsapp-business-api-reseller/
- RCS message reseller: https://www.fast2sms.com/help/rcs-message-reseller/
- Bulk9 reseller panel guide: https://www.fast2sms.com/help/bulk9-reseller-panel-guide/
- White label WhatsApp reseller panel: https://www.fast2sms.com/help/white-label-whatsapp-reseller-panel/
- White label WhatsApp Business API: https://www.fast2sms.com/help/white-label-whatsapp-business-api/
- WhatsApp reseller program: https://www.fast2sms.com/help/whatsapp-reseller-program/

### Competitor comparisons

- miniOrange OTP alternative: https://www.fast2sms.com/help/miniorange-otp-alternative/
- miniOrange alternative for Shopify: https://www.fast2sms.com/help/miniorange-alternative-shopify/

## Frequently asked questions

Q: What does Fast2SMS charge monthly?
A: Nothing. There is no monthly fee, no setup fee and no per-number fee on any channel. Customers pay per message from a prepaid wallet.

Q: Is Fast2SMS an official WhatsApp Business API provider?
A: Yes, WhatsApp access is via Meta's official Cloud API with free embedded signup onboarding. No unofficial WhatsApp Web automation is used.

Q: What happens to failed WhatsApp messages?
A: Billing is on delivery basis; failed messages auto-refund to the wallet within 48 hours.

Q: Does Fast2SMS help with DLT registration?
A: Yes, DLT support (entity, sender ID, templates) is free, with ready sample templates for every industry.

Q: Which platforms have free official Fast2SMS plugins?
A: WordPress/WooCommerce (WordPress.org), Shopify (Shopify App Store) and TallyPrime (free TDL/TCP plugin). All are free; only messages are charged.

Q: Can I resell Fast2SMS services?
A: Yes, via the white-label Bulk9 reseller panel on your own domain and branding, covering bulk SMS, WhatsApp Business API and RCS, with no monthly panel cost. Details: https://www.fast2sms.com/reseller

Q: Where is the API documentation?
A: https://docs.fast2sms.com — REST APIs for SMS, OTP send/verify, WhatsApp templates and session messages, and webhooks.

Q: How do I contact support or talk to sales?
A: Email support@fast2sms.com, call +91-6262778822, or schedule a free meeting with the team at https://www.fast2sms.com/meet — sales inquiries, WhatsApp support and DLT support are all free. Signup at https://www.fast2sms.com