You install a new AI code editor, sign in, and hit a wall. The tool wants a mobile number and a six-digit code before it unlocks the free tier.
Most developers read that as data collection. The real reason is cost.
Cursor’s phone verification follows the same pattern as most AI products. The check exists to make free accounts expensive to farm.
Why Do AI Coding Tools Ask for a Phone Number?
They want to stop one person from collecting many free allowances. Each free account carries a budget of model requests, and the company pays for that budget in advance.
A phone number ties that budget to something harder to copy than an inbox.
How Much Does a Free AI Account Actually Cost?
A traditional SaaS free tier costs almost nothing to give away. One extra user on a project board adds a few database rows. Ten fake accounts barely register.
AI assistants work differently. Every completion, chat reply, and agent run calls a large model. Every call carries a real inference cost.
That cost keeps running after launch, too. Cloud inference creates a per-request expense that continues long after a product ships, so a free tier never behaves like a one-time marketing giveaway.
Now attach that allowance to each account. Opening many accounts multiplies the allowance. Scripts that register accounts in bulk, harvest the credits, and move on are not hypothetical. Any per-account quota worth more than the effort of creating an account invites them.
Why Doesn’t Email Verification Stop Free-Tier Abuse?
Email costs nothing to multiply. Disposable inboxes take one search to find. A single domain with a catch-all mailbox produces unlimited addresses.
To a fraud team, an email proves one thing: someone can read mail. It says nothing about whether that someone is a distinct person.
A phone number carries more weight. It links to a SIM card, a carrier contract, or at least a paid line. Most people own one or two.
Here is the trade-off in a table:
| Signal | Phone number | |
| Cost to create | Near zero | Real, per number |
| Supply per person | Unlimited | One or two |
| Friction for a first account | Low | Low |
| Friction for a hundredth account | Low | High |
| Abuse resistance | Weak | Moderate |
That last gap is the whole point. The check barely slows a legitimate newcomer. It slows a farmer badly.
What Does a Phone Verification Check Actually Look At?
The code is only the visible part. Behind it, many sign-up flows examine the number itself.
- Number type. Internet calling services generate numbers cheaply and in bulk. Platforms across the industry often treat them with more suspicion than carrier-issued mobile numbers. Some reject them outright.
- Reuse. A number that has already verified several accounts on the same service tends to trip a limit.
No single signal decides the outcome. Together they raise the price of scale.
How Does Cursor Handle Sign-Up Verification?
Cursor lets people sign up with email, Google, or GitHub. For some new accounts, the editor then adds a text-message step before the free allowance opens.
Developers who sign in through a GitHub account with its own verification history often skip that step. The platform already trusts the account, so it asks for less.
That detail reveals a design choice. Vendors would rather borrow trust from an existing identity than ask every user for a number.
What Should Developers Know Before Sharing a Number?
Three practical points matter.
- The number becomes part of the account. Login alerts and account recovery may rely on it later. Use a number you will control for as long as you use the tool. A throwaway line works for a trial you plan to abandon. It fails for an account that holds billing details or team access.
- One free account per person is the norm. Terms of service usually say so, and verification enforces it. Workarounds tend to end in suspension, not bonus credits.
- Some people need a second number for legitimate reasons. Anyone who keeps work and personal identities apart, or who travels without access to their usual SIM, falls into this group. Solve it deliberately, before a verification screen forces a rushed choice.
Will Phone Verification Stay in AI Sign-Up Flows?
Probably, and the logic holds across vendors. Anthropic’s Claude Code, for example, shows how another provider draws the line between free access and usage limits, because every request costs money to serve.
The filter is imperfect. Determined abusers still buy numbers. Some honest users will always find the step intrusive.
But as long as AI tools give away something that costs real money per request, providers will demand proof that each account belongs to a separate person. The phone number is simply the cheapest proof available today.
That explains the text message sitting between developers and their first line of AI-generated code.
Related: Is Vibe Coding Bad? The Real Risks of AI Coding in 2026
