Referrals

Every ImtehanHub account ships with a 6-character referral code at sign-up. Share that code with your classmates, your school friends, your cousins. When three people sign up using your code, you automatically get one month of Pro — no payment screen, no admin approval, no waiting.

TL;DR — Get your code at /app/profile. Share the link. Three referrals = one free Pro month. The grant happens within minutes of the third signup.

How the code is generated

Codes are 6-character Crockford Base32 strings (23456789ABCDEFGHJKLMNPQRSTUVWXYZ — no 0, O, 1, I, L to avoid look-alikes). Generated server-side at sign-up. We collision-check against the global referralCodes/ index and regenerate if needed.

A typical code looks like 9PK4HR or M3N72B.

The code is permanent for the lifetime of your account — you cannot rotate it, and we never reuse codes from deleted accounts.

How to share

Three surfaces:

1. /app/profile — your code appears under "Referrals" with a Copy button and a pre-built share link.
2. Share link — https://imtehanhub.aoneahsan.com/?source=referral&ref=YOUR_CODE. Friends who open this link land on the homepage with your code pre-filled in the sign-up form.
3. /app/referrals — a dedicated page with your code, a count of completed referrals, the in-flight count, and a list of past referral events (anonymised — only "Referral #1, joined 2026-04-12").

The recommended share is via WhatsApp / Telegram — most Pakistani students use one or both. A pre-formatted message is one tap away on the Profile page.

How a friend signs up with your code

1. They open the share link, or open the regular homepage and click Sign in with Google.
2. The sign-up form has a "Referral code" field. The share link auto-fills it; manual sign-ups can paste it.
3. They complete Google sign-in.
4. The first time their account is created, the backend runs the referral pipeline (described below).

The pipeline:

• Looks up the code in referralCodes/{code} and resolves the referrer's UID.
• Runs anti-abuse checks (see below).
• If the checks pass, increments the referrer's referralCount and appends a row to users/{referrerUid}/referralEvents/{newUid}.
• If the increment crosses the milestone, grants the referrer one month of Pro.

Most of this happens in ~1 second. The referrer sees the count update on their next visit to /app/referrals.

The milestone — 3 referrals = 1 month Pro

The current milestone is 3. On the third successful referral, the referrer's account is automatically granted:

• plan: 'pro'
• proExpiresAt: now() + 30 days
• proGrantedReason: 'referral_milestone_3'

If the referrer was already Pro (paid), the 30 days extend their existing expiry — there is no penalty for being already paid.

If the referrer hits 6 referrals, they get a second month. 9 referrals, a third month. Each milestone is 3 referrals.

Anti-abuse checks

Three checks run on every inbound referral, in order:

1. Self-referral — if the new user's email matches the referrer's email (case-insensitive, after Gmail dot-and-plus normalisation), the referral is rejected. Logged to referralAuditLog as self_referral_blocked.
2. Same-device peer — if the new user signs up from a device fingerprint already used to sign up a different account that referred this code, the referral is held for manual review.
3. Mass-signup rate limit — if a single referrer accumulates more than 10 referrals in 24 hours, further referrals queue for manual review rather than auto-counting.

Failed-check referrals do not count toward the milestone but also do not penalise the referrer. We do not punish good-faith oversharing.

Reconciliation — what if my Pro grant is missing?

Edge cases happen — a flaky network during the third referral signup, a referral that was held for review and later cleared. The referralService.reconcile() function runs on every sign-in and:

• Counts your referralEvents rows.
• Compares against expected milestones.
• If you are owed a Pro grant that never landed, grants it (with proGrantedReason: 'referral_milestone_3_reconciled').

You should never need to ask for a missing grant manually, but if you do — email aoneahsan@gmail.com and we will investigate.

What counts as a referral

A referral counts when all three of the following are true:

1. The new user signs up with your code present in the form (auto-filled or pasted).
2. The new user completes Google sign-in and creates an ImtehanHub account.
3. The anti-abuse checks pass.

A referral does not count if:

• The friend already had an ImtehanHub account before using your link.
• The friend signs up but the code field is empty.
• The friend is you on a second Google account (self-referral).

Referral events visible to you

Your /app/referrals page lists each event with:

• An incrementing number (#1, #2, ...).
• The date of signup.
• A masked email (a***@gmail.com) so you can recognise it but no one else can.
• Status (counted / held for review / rejected).

You do not see the friend's full email, display name, or any other PII. Same privacy bar as the leaderboard.

What the friend gets

The friend does not get a discount or extra trial tests from using a referral code. The benefit is one-sided to the referrer.

We deliberately did not build a "both get something" structure because it tends to drive low-quality signups (people get a code from a stranger just to claim the friend-side perk). One-sided keeps incentives aligned: you share with people you actually know.

Common questions

Can I refer my younger sibling?

Yes, as long as they sign up on a different Google account. Same household is fine. The self-referral check is by email, not IP.

What if a friend already has an account?

Their signup does not count. We do not award referrals retroactively. Encourage them to make a new account on a different Google address if they really want to help — but that crosses into self-referral territory if it is your sibling's address.

Does the referral pipeline work on the mobile app?

Yes — the Android app reads the same ?ref= query string. Share links work universally.

Can my institute use the referral system?

Institutes have their own bulk pricing path; referrals are for individual students. See Institutes overview.

Next

• Billing — Pro / Unlimited / Add-on plan details.
• Free trial — the 3-test counter.
• Profile — find your referral code on the Profile page.