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- The Short Answer<\/a><\/li>\n\n\n\n
- TL;DR<\/a><\/li>\n\n\n\n
- The Six Variables That Decide Your Bill<\/a><\/li>\n\n\n\n
- Variable One: The Credit, Not the Message<\/a><\/li>\n\n\n\n
- The Encoding Cliff: One Character Can Triple Your Bill<\/a><\/li>\n\n\n\n
- Counting Segments Correctly in Code<\/a><\/li>\n\n\n\n
- Pricing a Message Before You Send It<\/a><\/li>\n\n\n\n
- Variable Two: Route Class<\/a><\/li>\n\n\n\n
- What the Published Slabs Actually Say<\/a><\/li>\n\n\n\n
- Variable Three: Volume Slabs and the Commitment Trap<\/a><\/li>\n\n\n\n
- Variable Four: Where the Deduction Actually Happens<\/a><\/li>\n\n\n\n
- Variable Five: Retry Amplification<\/a><\/li>\n\n\n\n
- Variable Six: DLT and the Costs That Are Not Per-SMS<\/a><\/li>\n\n\n\n
- DND Scrubbing and Who Pays for a Blocked Message<\/a><\/li>\n\n\n\n
- International SMS: A Different Cost Model Entirely<\/a><\/li>\n\n\n\n
- Reconciling Your Bill Against the DLR API<\/a><\/li>\n\n\n\n
- How to Model Your Monthly Bulk SMS Cost<\/a><\/li>\n\n\n\n
- A Worked Example<\/a><\/li>\n\n\n\n
- Cost Reduction Checklist<\/a><\/li>\n\n\n\n
- Channel Cost Decision Matrix<\/a><\/li>\n\n\n\n
- Ten Costly Mistakes<\/a><\/li>\n\n\n\n
- Frequently Asked Questions<\/a><\/li>\n<\/ol>\n\n\n\n
\n\n\n\nThe Short Answer<\/h2>\n\n\n\n
Your bulk SMS<\/a><\/strong> bill in India is the per-credit rate multiplied by the number of credits consumed, and almost every unpleasant surprise comes from the second term, not the first. A message is billed in credits, a credit covers 160 characters of GSM-7 text or only 70 characters of Unicode, and a single character outside the GSM-7 set flips the whole message to Unicode and can turn a one-credit send into three. On top of that, credits are deducted when a message is successfully submitted to the operator rather than when it is delivered, route class changes the rate by a third or more, DLT registration adds fixed costs outside the per-SMS rate, and a naive retry loop multiplies everything. Comparing providers on the advertised paise figure alone tells you almost nothing about what you will actually spend.<\/p>\n\n\n\n
![\"Diagram](\"https:\/\/www.smsgatewaycenter.com\/blog\/wp-content\/uploads\/2026\/08\/bulk-sms-pricing-india-cost-drivers.webp\")
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\n\n\n\nTL;DR<\/h2>\n\n\n\n
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- You are billed per credit, not per message.<\/strong> One credit equals 160 GSM-7 characters or 70 Unicode characters. Concatenated messages drop to 153 and 67<\/a> per segment because the User Data Header eats space.<\/li>\n\n\n\n
- One non-GSM-7 character re-encodes the entire message.<\/strong> A curly apostrophe, an em dash, an emoji or a rupee sign pushes a 155-character message from one credit to three.<\/li>\n\n\n\n
- Route class matters more than negotiation.<\/strong> On the published SMSGatewayCenter slabs, transactional at 50,000 units is INR 0.15 per SMS while promotional at the same volume is INR 0.13, and the routes have different delivery windows, sender ID types and DND behaviour.<\/li>\n\n\n\n
- Deduction happens at successful submission to the operator, not at delivery.<\/strong> The published terms state credits are non-refundable once the SMS is successfully submitted. Undelivered does not mean unbilled.<\/li>\n\n\n\n
- Retries are the most common source of unexplained overspend.<\/strong> Retrying a permanently failed message three times triples the cost of that message and buys nothing.<\/li>\n\n\n\n
- DLT is a fixed overhead layer<\/strong>, not a per-SMS charge, but template rejections and mismatches cause failed sends that still consume operational time and can cause resend cost.<\/li>\n\n\n\n
- Price the message before you send it.<\/strong>
POST https:\/\/unify.smsgateway.center\/SMSApi\/info\/msg<\/code> returns encoding, length, remaining characters and credit count for any message string.<\/li>\n\n\n\n- Reconcile against delivery reports.<\/strong> The DLR API returns per-message
cost<\/code> andlength<\/code> fields, which is the only way to audit a bill against reality.<\/li>\n<\/ul>\n\n\n\n
\n\n\n\nThe Six Variables That Decide Your Bill<\/h2>\n\n\n\n
Most bulk SMS pricing articles are a table of provider names and paise figures. That is a comparison of list prices, not a cost model. Here is the actual structure of the bill:<\/p>\n\n\n\n
- One non-GSM-7 character re-encodes the entire message.<\/strong> A curly apostrophe, an em dash, an emoji or a rupee sign pushes a 155-character message from one credit to three.<\/li>\n\n\n\n
- TL;DR<\/a><\/li>\n\n\n\n
![\"Diagram](\"https:\/\/www.smsgatewaycenter.com\/blog\/wp-content\/uploads\/2026\/08\/encoding-cliff.webp\")
<\/a><\/figure>\n\n\n\n