Subscription models work for daily users; pay-per-session works for occasional ones. The break-even is around 6–8 sessions per month for a £14/month plan. This guide compares the four AI tutoring pricing models and tells you which fits your family.

The four models

Model Examples Typical UK price Best for
Subscription (flat) aitutors.me (£14/mo), Khanmigo (~£3/mo) £3–25/month Daily or near-daily users
Pay-per-session Some boutique services £2–8/session Occasional, "homework rescue" use
Freemium Khan Academy + Khanmigo, ChatGPT-style £0 base, paid upgrade Trial-then-decide
School-funded CENTURY Tech, Sparx £0 to family School-provided users

Subscription: when it makes sense

The maths

For a £14/month subscription with unlimited sessions:

Sessions/month Cost per session
4 £3.50
8 £1.75
16 £0.88
30 £0.47
60 £0.23

Below ~6 sessions/month, you're overpaying. Above 8 sessions/month, subscription is dramatically cheaper than any per-session model.

When subscription wins:

  • Your child uses the tutor 3+ times per week
  • You're trying to build a daily 20-minute habit
  • You don't want booking friction
  • You expect 12+ months of consistent use

When subscription doesn't make sense:

  • Pre-exam crunch only (use freemium for the month)
  • Your child uses it sporadically
  • You're not sure if they'll engage long-term
  • One-off subject difficulty (e.g. "I just need help with Year 8 ratio")

Pay-per-session: when it makes sense

When it wins:

  • You expect <6 sessions/month
  • Specific topics, not general practice
  • One-off "stuck on this homework" use
  • You're hesitant to commit to a subscription

When it doesn't:

  • Daily use (much more expensive)
  • Habit-building goals (friction kills the habit)
  • Multiple topics over multiple weeks

Freemium: the gateway

Khan Academy + Khanmigo's free tier is a legitimate option. The free tier covers most KS3 maths topics adequately. The paid Khanmigo subscription unlocks the AI tutor on top.

Best move: start free for 2 weeks. If your child engages, decide whether the paid tier or another subscription (aitutors.me, MedlyAI) fits better.

School-funded: the unbeatable price

If your school provides CENTURY Tech or Sparx Maths, your child gets a real AI-powered tool at £0 cost to the family. The downside: not chosen by you, and may not match your child's learning style.

The smart move: use the school-funded tool first. Add a subscription only if there's a gap (most commonly: Sparx doesn't tutor — see aitutors.me vs Sparx Maths).

The trial period rule

Any subscription you can't try free for 7–14 days is one you should be sceptical of. AI tutoring is impossible to evaluate from a marketing page — only your child's actual engagement tells you.

aitutors.me, Khanmigo, and most reputable services offer trials. Use them.

The annual upsell trap (and the genuine annual deal)

Some services offer "annual = 2 months free". This is real value if:

  • You've already used the monthly plan for ≥3 months
  • Engagement is consistent
  • You expect at least 12 more months of use

It's not value if:

  • You're at month 1 of a trial
  • You're not sure your child will stick with it
  • You haven't checked the cancellation policy

Rule: never sign annual on a free trial. Run monthly for 2–3 months, then decide.

How aitutors.me thinks about pricing

(Disclosure: I run aitutors.me. This is the pricing rationale.)

  • £14/month Founding for the first 100 families — locked for life. Anchors below £19/month (the impulse-buy threshold for parents).
  • £24/month standard after the first 100. Slightly above £19 because the Founding deal is designed to be a real discount.
  • 14-day free trial. Cancel anytime, no contract.
  • Annual upsell only after Day 12 of the trial (when engagement has signal) — not at signup.

Many subscription tutors over-charge at MVP because they need runway. The right move (in my view) is to under-charge early and rely on referrals once the product is proven.

Decision framework

How many sessions/week do you expect?
├─ 0–1: pay-per-session or freemium
├─ 2–3: freemium first, then subscription if engagement holds
├─ 4–6: subscription (any reasonable one)
└─ 7+: subscription only — pay-per-session is uneconomic

Does your school provide a free AI tutor?
├─ Yes: start there. Add only if there's a gap.
└─ No: subscription with free trial is the default move

FAQ

Is a subscription AI tutor better value than pay-per-session?

Yes for daily users (4+ sessions/week). For occasional use, pay-per-session or freemium is cheaper. Break-even is typically 6–8 sessions/month at £14/month.

Are AI tutor subscriptions worth it?

For habit-formers, yes. Daily 20-min sessions × 4 weeks = ~80 sessions for £14 = <£0.20/session. Cheaper than any human tutoring.

What's the cheapest AI tutoring option in the UK?

Free if school-provided (CENTURY, Sparx). Otherwise: Khan Academy + Khanmigo (~£3/month).

Written by Jason at aitutors.me. Updated 20 May 2026.