# Check if a phone number can receive RCS messages

> Check in bulk whether phone numbers can receive RCS messages, with the handset platform when reported. Only conclusive answers are charged.

Canonical: https://mobilevalidate.com/services/rcs-capability-check · Last updated: 2026-09-25

![A phone with chat bubbles; one messaging-app check says registered, another is unknown.](https://mobilevalidate.com/images/messaging-app-registration-check.svg)

*Messaging-app checks answer registered, not registered or unknown, with the time we checked.*


The RCS check tells you whether phone numbers can currently receive RCS messages: the richer successor to SMS built into phone messaging apps. It runs in bulk jobs and answers `registered: true`, `false` or `null` (unknown) per number. When the handset platform is reported, it adds `device_os` (`ios`, `android` or `unknown`). Nothing is sent to the number.

## What does the RCS check tell you?

It answers whether the number is RCS-capable right now. Unlike app-based messengers, RCS is not an account someone signs up for. It is a feature of the carrier network and the phone's default messaging app, standardised by the GSMA as the Universal Profile. On Android it runs in the messaging app; Apple added RCS to iOS 18 in 2024. It works only where the carrier supports it and the user has not turned it off.

- `registered: true`: the number can receive RCS messages. `attributes.device_os` may say whether the handset runs iOS or Android.
- `registered: false`: a conclusive answer that the number is not RCS-capable now. Messages to it would be delivered as SMS or MMS.
- `registered: null`: no conclusive answer; not charged.

Capability changes more often than messenger registrations do: a new phone, a disabled setting or a carrier change can flip it. Keep `max_age` short when you use the answer to route messages.

## Who uses it, and why?

- **RCS business messaging rollouts.** Brands adopting RCS for verified, branded messages check which opted-in customers can receive them and send SMS to the rest. See [SMS cost reduction](/use-cases/sms-cost-reduction).
- **Channel selection.** RCS can carry rich cards, suggested replies and read receipts for messages people asked for, such as delivery updates or appointment confirmations. See [channel selection](/use-cases/channel-selection).
- **Device platform awareness.** `device_os` tells teams whether a customer is on iOS or Android without asking, which helps choose between app push, [iMessage](/services/imessage-number-check)-friendly formats and RCS.
- **Deliverability signal.** RCS capability shows a live number on a smartphone with a supporting carrier, which complements a [carrier lookup](/services/carrier-lookup).

## What do you get back?

Each job row carries `checks["rcs.registered"]`.

| Field | Type | Meaning |
|---|---|---|
| `registered` | boolean or null | `true` RCS-capable, `false` not capable, `null` unknown |
| `attributes.device_os` | enum `ios`, `android`, `unknown` | Handset platform reported with the capability, when available |
| `status` | enum | `completed`, `pending`, `unknown`, `unsupported_country` or `failed` |
| `confidence` / `confidence_score` | enum / 0–1 | How sure the answer is |
| `checked_at` | timestamp | When the answer was obtained |
| `cached` / `age_seconds` / `billed` | boolean / integer / boolean | Cache and billing details |
| `reason` | string or null | Why the answer is not conclusive |

Downloads include an `rcs.registered.device_os` column.

## How is it billed?

Per number, for conclusive answers only, at the bulk price. You're not charged for inconclusive results (unknown, unsupported country, timeout, invalid, duplicate). The free `POST /v1/jobs/estimate` shows the maximum cost before you start. See [pricing](/pricing).

Answers your account received recently can be served from its cache at no charge. Because capability changes, consider a shorter `max_age` than for messenger checks. `max_age: 0` forces fresh, billed checks.

## What are the limits?

RCS runs in bulk jobs only. `POST /v1/lookup` refuses it with `403 service_disabled` ("The check 'rcs.registered' is available in bulk jobs only (POST /v1/jobs).").

- Up to 50,000 numbers and e-mails per job, 20 checks per request, 100,000 number × check pairs per job.
- All countries are accepted, but `true` answers only occur where carriers support RCS.
- Requests that look like sequential number ranges or generated e-mail lists are rejected.
- A daily number cap applies per account. Follow the job with `GET /v1/jobs/{id}?wait=30` or a [webhook](/docs/webhooks).

## How do I use it responsibly?

Use RCS capability to deliver messages people agreed to receive in a format their phone supports. Carrier and industry rules for RCS business messaging require verified senders and consent, and our [acceptable use policy](/legal/acceptable-use) forbids unsolicited bulk messaging and range scanning. Don't use `device_os` to infer anything about a person beyond the handset platform. People can object to checks via the [opt-out form](/opt-out).

## Example request

In test mode `+447700900001` answers capable, `…002` not capable and `…003` unknown. Test answers do not include `device_os`. See [test mode](/docs/test-mode).

```bash
curl https://api.mobilevalidate.com/v1/jobs \
  -H "Authorization: Bearer $MOBILEVALIDATE_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: rcs-demo-001" \
  -d '{"numbers": ["+447700900001", "+447700900002", "+447700900003"], "checks": ["rcs"]}'
# then: GET /v1/jobs/{id}?wait=30 and GET /v1/jobs/{id}/results
```

Job (excerpt, test mode):

```json
{
  "object": "job",
  "id": "job_0VWF4kFfnr2scbsj4bNU",
  "status": "completed",
  "livemode": false,
  "checks": [
    "rcs.registered"
  ],
  "created_at": "2026-09-25T14:25:29.875Z",
  "completed_at": "2026-09-25T14:25:29.879Z",
  "progress": {
    "total": 3,
    "checks_total": 3,
    "done": 3,
    "conclusive": 2,
    "non_billable": 3
  },
  "retention_days": 30
}
```

First row from `GET /v1/jobs/{id}/results` (test mode):

```json
{
  "kind": "phone",
  "input": "+44770*****01",
  "e164": "+447700900001",
  "country": "GB",
  "number_status": "valid",
  "checks": {
    "rcs.registered": {
      "service": "rcs.registered",
      "status": "completed",
      "registered": true,
      "attributes": null,
      "confidence": "high",
      "confidence_score": 0.99,
      "checked_at": "2026-09-25T14:25:29.879Z",
      "cached": false,
      "age_seconds": 0,
      "billed": false,
      "reason": null,
      "poll_after_ms": null
    }
  },
  "test": true
}
```

## Frequently asked questions

### What is RCS?

RCS (Rich Communication Services) is the carrier messaging standard that adds typing indicators, read receipts, high-resolution media and branded business messages to the phone's built-in messaging app. It is defined by the GSMA Universal Profile.

### Do iPhones support RCS?

Yes, since iOS 18 in 2024, where the user's carrier supports it. That is why the result can report device_os ios as well as android.

### Why can RCS capability change from one day to the next?

Capability depends on the carrier, the handset, the messaging app and whether the user has RCS chats turned on. A SIM moved to another phone, or a setting changed, can switch it on or off.

### Does RCS capability mean I can send RCS business messages?

Not by itself. Business messaging over RCS needs a verified sender and carrier approval, and it may only be used for messages the recipient agreed to receive.

### Why is device_os missing from some answers?

device_os is included only when it is reported with the capability answer. When it is not, the key is absent or unknown. Test-mode answers do not include it.

## Service code and modes

- Code: `rcs.registered` (input: phone number)
- Modes: bulk only · worldwide

## Price (live)

- Realtime: not available (bulk only)
- Bulk (POST /v1/jobs): $0.0003 per check ($0.30 per 1,000)
- You're not charged for inconclusive results (unknown, unsupported country, timeout, invalid, duplicate).

## Response fields (from the public catalog)

| Field | Type | Meaning |
|---|---|---|
| registered | boolean or null | true = found, false = not found, null = unknown (not charged) |
| status | enum | completed, pending, unknown, unsupported_country, failed |
| checked_at | timestamp | When the answer was obtained |
| attributes.device_os | enum (ios, android, unknown) | Handset platform reported with the RCS capability. |

_Platform and brand names are used only to describe which service a check refers to. MobileValidate is not affiliated with, endorsed by or sponsored by any of these companies; all trademarks belong to their owners._