# Castel SIP vs MoSIP C5

The clearest difference is iOS requirement: MoSIP C5 at 11.0 against Castel SIP's 15.5. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Castel SIP ships an update every 4 months, MoSIP C5 every 2 months. The most recent releases landed on November 1, 2026 and June 3, 2026 respectively.

## The numbers

| Metric | Castel SIP | MoSIP C5 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 84 MB | 90 MB |
| Requires iOS | 15.5 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Castel](https://appshunter.io/developer/566301834) | [voxvalley technologies pvt ltd](https://appshunter.io/developer/464573923) |

## What reviewers say

### Castel SIP

[App page](https://appshunter.io/ios/app/castel-sip/id566301831)

This application functions as a SIP intercom softphone, enabling users to make and receive audio and video calls from IP intercom stations on their mobile devices. It allows for communication and remote door opening, working through Wi-Fi and cellular data networks.

**Highlights:** Audio and video calls, IP intercom station integration, Remote door opening, Address book with favorites, Call history, Remote commands during calls

**Features:** macOS Compatibility

**In-app purchases:** none


### MoSIP C5

[App page](https://appshunter.io/ios/app/mosip-c5/id1043453517)

**Features:** macOS Compatibility, Siri integration

**In-app purchases:** none


## Frequently asked questions

### Is Castel SIP free?

Castel SIP is free to download, with no in-app purchases.

### Is MoSIP C5 free?

MoSIP C5 is free to download, with no in-app purchases.

### Do Castel SIP or MoSIP C5 have ads?

Neither Castel SIP nor MoSIP C5 shows ads.

### Which is updated more often, Castel SIP or MoSIP C5?

Castel SIP ships an update every 4 months, and MoSIP C5 every 2 months. Most recently, Castel SIP was updated on November 1, 2026 and MoSIP C5 on June 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*