Gym Chain Member App and Class Booking: Custom Build Cost in London (2026)

The verdict in three sentences

Beyond 4 gyms, software billed as a percentage of revenue costs more every year than maintaining a custom platform, because the bill tracks your growth while the service stays the same. For 3,200 members in London, the current bill reaches about 45,000 EUR a year (around 38,000 GBP), against 12,000 EUR of maintenance for a proprietary tool built for 45,000 to 80,000 EUR excluding VAT. Break-even lands between 2 and 3 years, and every new site brings it closer.

What your current software really costs

The "1.5% of revenue plus a per-site fee" model feels painless when you open your first gym. It gets heavy as average membership value and site count rise. With an average membership of 45 EUR per month, 3,200 members generate 1,728,000 EUR of annual revenue.

Flat-fee SaaS is therefore a real alternative, cheaper than your current contract. Custom makes sense when you want to own the member experience, your data and your roadmap, or when off-the-shelf tools cannot handle your model (multi-site memberships, premium classes, corporate partnerships).

What a 45,000 to 80,000 EUR custom platform includes

The sensitive technical point is mandate migration: Bacs Direct Debit mandates must move to the new collector without members signing again, usually through a bulk change of service user number. It is doable with your payment provider if you plan it 6 to 8 weeks before cutover.

Timeline and migration risks

A project like this takes 4 to 6 months: 6 weeks of scoping and mockups, 12 to 16 weeks of development, 3 weeks of testing on a pilot gym, then cutover of the other three. The main risk is the overlap period (old and new software), to budget over 2 months, about 7,500 EUR in your case. Also check the exit clause of your current contract: a 3 to 6 month notice period is common.

Mini case study

Tom, founder of 4 gyms in London (3,200 members), pays 45,120 EUR a year today. He chooses a platform at 65,000 EUR and a maintenance and hosting package of 1,000 EUR per month, or 12,000 EUR a year. Annual saving: 45,120 - 12,000 = 33,120 EUR. Adding 7,500 EUR of overlap during migration, the total investment is 72,500 EUR, paid back in about 26 months. If he opens a fifth gym with 800 members, the old software would have cost 11,280 EUR more per year, against zero additional licence cost on his platform. With only 3 gyms, the same calculation gives a payback close to 3 years.

FAQ

Is custom software worth it for a single gym?

Rarely: with 800 members, the 1.5% commission is about 6,500 EUR a year, not enough to recover 45,000 EUR in under 5 years. A flat-fee SaaS at 250 to 500 EUR per month is the right choice then.

What happens to existing Direct Debit mandates?

They are migrated to your new payment provider without members signing again. Allow 4,000 to 8,000 EUR for the full data migration.

How long does app store publishing take?

Plan 1 to 2 weeks for Apple review and a few days for Google. Building the full member app takes 10 to 14 weeks.

Are our current turnstiles compatible?

In most cases yes, through the existing access controller or a gateway box at 300 to 600 EUR per entrance. A one-day audit confirms it before the quote.

Who owns the code and the data?

You do, fully, through an assignment of rights in the contract. Member data stays hosted in the UK or EU, in line with UK GDPR.

Let's scope your project. Tell us your number of gyms, members and your current contract: we price a platform between 45,000 and 80,000 EUR and your exact 3-year break-even. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.