DND Filter API India | API Integration & Documentation

What is the MetaReach DND Filter API?

The MetaReach DND Filter API is a programmatic service for checking the DND status of Indian mobile numbers. Businesses integrate DND checks into their CRM, lead forms and messaging workflows to identify numbers that should be excluded from promotional communication.

It is built for development teams at businesses and platforms that send promotional SMS or calls in India: CRM and lead-management systems, e-commerce and fintech apps, campaign tools, and agencies running campaigns for clients. If you only need to check a list now and then, the web-based DND number checker does the same job without any code.

Where DND Data Comes From

In India, a subscriber's Do Not Disturb choice is recorded in the National Customer Preference Register (NCPR) under TRAI's Telecom Commercial Communications Customer Preference Regulations (TCCCPR), 2018. Subscribers can block all promotional messages or only certain categories, such as banking or real estate, and can change that choice at any time through their operator, the 1909 short code or the TRAI DND app.

Two things follow for anyone checking DND status:

A result reflects the preference recorded when the check ran. Because preferences change, re-check a list before each campaign rather than reusing an old result.
Operators also scrub promotional traffic against DND preferences at the time of delivery through the DLT system. Checking in advance does not replace that; it keeps your own lists clean, so you don't pay to send messages that will be blocked.

MetaReach receives the DND status data behind the API through its telecom operator connections, not from a self-maintained copy of the register, and the data is refreshed every day. For the regulations themselves, see the TRAI website.

How DND Checking Fits a Messaging Workflow

Most teams use the API at two points:

At capture. When a number enters your system through a sign-up, lead form or CRM import, your server checks it and stores the DND status on the contact record.
Before a campaign. A scheduled job re-checks the promotional segment shortly before the send, because DND preferences may have changed since capture.
At send time. Your campaign tool excludes contacts marked DND for that category from promotional messages, while service messages to existing customers follow their own DLT category rules.
Afterwards. Opt-outs you receive directly are added to your own suppression list too, because a customer who replied STOP to you may not have registered on DND.

For the promotional sends themselves, our bulk SMS with DND filtering applies the same check inside the sending platform.

DND Status Is Not the Same as Permission to Send

A DND check answers one question: has this subscriber registered a DND preference? It does not decide whether a particular message is allowed. That depends on the message category registered on DLT, whether you hold the customer's consent, the 9 AM to 9 PM window for promotional messages, the opt-out requirement and the data-protection duties under the DPDP Act. A number that is not on DND can still be the wrong recipient if you have no consent, and a DND number can still receive genuine service messages such as OTPs and order updates under the correct template category.

Our DND filter page explains the categories in more detail, and DLT registration support covers how templates are categorised.

API Access and Documentation

Access is issued per business. Once your account is set up, your developers receive:

The API reference: endpoint, HTTP method, required headers, request parameters and validation rules.
Credentials and the authentication method for your account.
Example requests and responses, including the error format and how invalid numbers are reported.
The rate limits and request-size limits for your plan.

We share the reference directly rather than publishing a public spec, so your team always builds against the current version for your account. Store credentials on your server only; never put them in browser JavaScript or a mobile app.

Developer support: info@metareachmarketing.com or +91 7669999219, Monday to Saturday, 10:00 AM to 6:00 PM IST. If you also send SMS through us, the SMS API documentation covers sending, delivery reports and balance checks.

Request API Access

Pricing

DND checks are a paid service, billed on the number of checks, with rates that fall as volume rises. The same applies to the DND number checker. Rate limits depend on your plan. Contact our team with your expected monthly volume for a quote.

Frequently Asked Questions

What is a DND Filter API?

A DND Filter API lets your software check whether an Indian mobile number has a Do Not Disturb (DND) preference recorded, without anyone opening a web tool. Your CRM, lead form or campaign platform sends the number and gets its DND status back, so you can keep DND numbers out of promotional sends.

How does the MetaReach DND Filter API work?

Your system sends one or more mobile numbers to the API over HTTPS with your account credentials. The API returns the DND status for each number, which your system stores against the contact or uses to decide whether a promotional message should be queued. The exact endpoint and request format are shared with your developers during onboarding.

Does the API support single-number and bulk-number checks?

Both use cases are discussed during onboarding: an inline check when a single number is captured, and a batch check before a campaign. The request limits for each mode are confirmed for your account, so please ask our team before you design a high-volume batch job.

How do developers authenticate API requests?

API access is issued per business account. Your team receives credentials and the authentication method with the API reference when access is set up. Keep the credentials on your server; never place them in front-end JavaScript or a mobile app.

What information does the API return?

For each number, the API returns whether a DND preference is recorded. The full response fields, and how errors and invalid numbers are reported, are documented in the API reference your team receives on onboarding.

What are the API's rate limits and pricing?

DND checks are a paid service, billed on the number of checks, with rates that fall as volume rises. Rate limits depend on your plan. Contact our team for a quote and the current limits for your expected volume.

How frequently is DND status information updated?

Subscribers can register or withdraw a DND preference at any time, so no DND result stays valid forever. The data behind the MetaReach API is refreshed every day, so a preference registered today can show up in tomorrow's checks. Re-check a list before each campaign instead of reusing an old result.

How can developers obtain API access?

Request access through the contact form or WhatsApp. We confirm your use case and expected volume, set up your account, and share the credentials and API reference with your developers.

Request API Access Chat on WhatsApp

DND Filter API India: DND Status Checks for Your CRM & SMS Platform