SIM cards are not strictly required for every multi-account setup, but they solve the two hardest problems: trusted network identity and platform phone verification. Without SIM cards, you need alternative solutions for both. Mobile proxies can replace the network identity function. Virtual numbers can sometimes replace phone verification. But neither alternative is as reliable as a physical SIM. The cost of mobile proxy bandwidth is $5.60-11 per GB, and building your own SIM-equipped farm breaks even around 50-100GB/month. For related infrastructure decisions, see our guide on whether you need proxies for multi-account.
The fundamental question is not "do I need SIMs" but "do my accounts need individual network identities that platforms trust?" The answer is almost always yes. How you achieve that — SIM cards, mobile proxies, or a managed service — is the implementation decision.
What Problems Do SIM Cards Solve?
Network identity. A SIM card associates your device with a carrier network. The IP address assigned through that carrier connection is a mobile IP — the most trusted proxy type. Mobile IPs have high trust because carriers share them across thousands of legitimate users, giving each IP an extensive legitimate browsing history. Platforms treat mobile IP traffic as presumptively legitimate in ways they do not treat datacenter or residential proxy traffic.
Phone verification. Platforms including Instagram, TikTok, WhatsApp, and Telegram require phone-verified accounts for full functionality. These platforms increasingly block VoIP and virtual numbers, making physical SIMs one of the few reliable verification methods. An account that cannot pass phone verification when prompted is an account at risk of being locked.
Carrier signal consistency. SIM cards provide consistent carrier identity signals (MCC/MNC codes) that match the device's reported location and IP geolocation. When a device claims to be in the US on a T-Mobile SIM, the IP, carrier code, and location need to align. Mismatches — a device with a US IP but an international carrier code — are a detection trigger.
Can You Use Just Proxies Instead of SIMs?
Proxies can replace the network identity function of SIM cards but not the phone verification function.
A mobile proxy assigned per device gives each account a unique IP with carrier-level trust, similar to what a physical SIM provides. Residential proxies provide moderate trust. Datacenter proxies provide low trust and should not be used for multi-account operations.
The limitation is verification. If a platform requires SMS verification and you do not have a SIM — or a virtual number service that the platform accepts — you have no way to complete the verification. This risk compounds at scale. One verification challenge on one account is manageable. Verification challenges across a 50-account portfolio without SIM cards is a crisis.
Unlimited data plans from major carriers run approximately $30/month per line in the US. For an 8-device setup, that is $240/month in data alone. This is why the SIM vs proxy decision is partly an economic one. At small scale, the cost and complexity of physical SIMs may not be justified if mobile proxies plus a reliable virtual number service handle your needs.
When Are SIM Cards Necessary?
Platforms that require phone verification. Instagram, TikTok, WhatsApp, and Telegram all have phone verification requirements. If you are running accounts on these platforms, physical SIMs provide the most reliable verification method.
High-value accounts. Accounts with significant audiences, monetization, or brand association justify the additional security of a dedicated SIM. Losing a high-value account to a verification challenge you cannot pass is far more expensive than the SIM's monthly cost.
Geographic targeting. If your accounts need to appear in specific countries, SIM cards from carriers in those countries provide the most convincing location signal. A TikTok account intended to reach US audiences that operates on a T-Mobile SIM with a US IP passes location checks natively.
Apps that require SMS receipt. Some apps explicitly check for active SIM cards. The MC Money app, referenced in Multilogin's phone farm guide, requires an active SIM in the device to receive paid SMS messages. Apps with similar requirements will not function without a SIM.
When Can You Skip SIM Cards?
Platforms that do not require phone verification. Some platforms are email-only or offer alternative verification. Know the requirements before assuming.
Small-scale operations with mobile proxies. If you are running 1-5 accounts and have access to high-quality mobile proxies and a phone verification service that works, the added complexity of physical SIMs may not be necessary.
Testing and experimentation. Before committing to SIM infrastructure, test your multi-account strategy with mobile proxies. If the accounts survive and grow, the validation justifies the SIM investment.
Managed services. When you use a managed distribution service like Conbersa, the SIM infrastructure is handled for you. Our device fleet already has carrier connections. You do not need to provision them.
How Conbersa Handles SIM Infrastructure
Conbersa runs every client account on a real physical device with a genuine carrier connection. SIM cards are part of our device infrastructure, not an add-on. Each device has its own network identity, its own carrier signal, and its own verification capability. Clients do not manage SIMs, carriers, or data plans. They get multi-account distribution on hardware that passes platform checks because every signal is real. For the broader infrastructure picture, see what real device infrastructure is.