# Apportionment

How the total cost of running the building is divided between the flats, using the shares or method set out in each lease.

Also called: service charge apportionment, service charge percentage, share of service charge.

Each lease says what share of the costs that flat pays. It might be a fixed percentage (for example 12.5% for each of eight equal flats), a share by floor area, or "a fair proportion" decided by the landlord or manager.

## Things to check

- **Do the shares add up to 100%?** If they add up to more or less, the leases may need varying. The tribunal can vary leases that don't make satisfactory provision for this (s.35).
- **Different schedules.** Some leases split costs differently for different things, such as the lift, the car park or the shops.
- **Non-residential units.** In an RTM building, if some units aren't held by qualifying tenants and the flats' shares come to less than 100%, the landlord pays the shortfall (s.103).

## Rounding

When you split a bill in pounds and pence, the parts must add up exactly to the total. A good method is to round each share down and give the leftover pennies to the largest remainders, so nobody is over-charged and nothing is lost.

You can't change the shares just because it seems fairer. The lease governs until it is varied.

## Related terms

- [Service charge](https://runyourblock.co.uk/glossary/service-charge)
- [Service-charge demand](https://runyourblock.co.uk/glossary/service-charge-demand)
- [Demised premises](https://runyourblock.co.uk/glossary/demised-premises)

## Sources

- [Landlord and Tenant Act 1987, s.35 (variation of leases: service charge computation)](https://www.legislation.gov.uk/ukpga/1987/31/section/35)
- [Commonhold and Leasehold Reform Act 2002, s.103 (landlord contributions to service charges)](https://www.legislation.gov.uk/ukpga/2002/15/section/103)

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Updated 22 October 2026. Source: https://runyourblock.co.uk/glossary/apportionment