Extension Code Number Masking: One Number, Many Private Contacts (2026)

Extension code number masking lets one masked phone number reach many people privately. Each person gets a short code; a caller dials the masked number, enters the code followed by # (or scans a QR that sends it), and is connected to that person. Neither side sees the other's real number. It suits vehicle tags, parcel labels, classifieds and society intercoms.

Set up extension codes: Open the Edesy masking portal. Switch a number to extension routing and create your first code.

How a call works

Caller dials +91 80XX XXX XXX  ->  enters 482193#  ->  connected to the person behind code 482193

1. The caller dials the masked number.
2. They hear a short prompt (default: "Please enter the code, followed by the hash key"). Digits sent by the phone interrupt the prompt.
3. They enter the code and #.
4. If the code is active, the target's phone rings. The caller hears ringback.
5. The target sees the masked number as the caller ID, not the caller's real number.
6. When the target answers, the call is bridged and billing starts.

What the caller hears

Extension codes vs sessions vs webhook routing

Edesy masking numbers have three routing modes. Choose per number.

If both people are known when you set up the call, sessions are usually the better fit; see the session API guide. Extension codes shine when the caller could be anyone.

Setting it up

1. Get a number. Buy an Indian number in the Edesy voice portal (KYC first), then enroll it in masking.
2. Switch it to extension routing:

PATCH https://voice-api.edesy.in/v1/masking/numbers/{number_id}/routing
{ "routing_mode": "extension",
  "extension_prompt": "Please enter the code, followed by the hash key." }

3. Create an extension:

POST https://voice-api.edesy.in/v1/masking/extensions
{ "target_number": "9876543210", "label": "Car MH12AB1234", "reference": "tag_000123" }

The response includes the code (6 random digits if you don't supply one) and dial_links, one per extension-mode number, each with a ready-made tel_uri.

4. Print or publish it. Put the tel_uri in a QR code or link, and print the number and code as text too.

You can also create, print and manage codes in the portal.

The extension object

Generated codes are random, not sequential, so people can't guess a neighbour's code. If you choose your own, don't make them sequential either.

Managing codes over time

• Pre-print tags: create extensions with status: "inactive" and no target. Activate each one when it is sold, with PATCH /v1/masking/extensions/{id} setting target_number and status: "active".
• Change the owner's number: update target_number. The next call uses it; the printed code doesn't change.
• Retire a code: set it inactive, or delete it. Past call logs keep the code.
• Find a code: list with filters for code, reference, status or a search term.

Events and logs

Your event webhook receives extension calls with direction: "extension", the extension_code and your reference: call.incoming when a valid code is entered, call.connected when the target answers, call.missed if they don't, and call.ended with the bridged duration. Invalid codes produce no event. Call logs can be filtered by direction and code.

What it doesn't do (yet)

Be clear with your users about the limits:

• One target per code; no fallback number.
• The target can't call the caller back through the code. They see only the masked number.
• No whisper or announcement to the target before connecting.

Cost

See number masking pricing and what number masking costs.

Read more on the extension codes feature page, the number masking hub and the number masking docs. For specific uses, see QR vehicle tags and parcel labels.