Result
Is your service charge demand too late?
If a cost was incurred more than 18 months before you were asked to pay it, you may not have to pay it at all. Enter two dates and see where your demand falls.
Landlord and Tenant Act 1985, section 20B · the "18-month rule"Result
Your timeline will appear here.
How the 18-month rule works
The clock starts when the cost is incurred
Usually when the landlord received the invoice or had to pay for the work or service, not when the work began.
The landlord has 18 months to ask you to pay
If the demand comes later, you are not liable for that cost. This applies to costs already incurred, so it mostly affects year-end balancing charges rather than budget (advance) demands.
Unless you were warned in writing in time
If, within those 18 months, you were told in writing that the cost had been incurred and that you would be asked to pay it, the landlord can still charge it later.
Changing in England from 1 April 2027. Under the Leasehold and Freehold Reform Act 2024, the written-warning exception becomes a "future demand notice". The 18-month limit stays. The rules on what that notice must contain had not been set when this calculator was last updated (3 November 2026), so for later English demands we show the result as worth querying. Wales is not affected.
Questions
What is the 18-month rule for service charges?
Under section 20B of the Landlord and Tenant Act 1985, you are not liable to pay service charge costs that were incurred more than 18 months before the demand was served on you, unless within those 18 months you were told in writing that the costs had been incurred and that you would be asked to pay them later.
What date counts as when a cost was incurred?
Usually when the landlord received the invoice or had to pay for the work or service, not when the work started. If you are unsure, use the invoice date and ask the landlord for the invoices.
Does the rule apply to advance (budget) demands?
The rule is about costs that have already been incurred. An advance demand based on a budget is usually not caught, but a year-end balancing charge for costs incurred long before can be.
What if I have already paid?
Paying a charge does not, by itself, mean you have agreed it. If you think a cost was demanded too late, write to the landlord or managing agent and ask them to explain or refund it. Free advice is available from LEASE.
Which date should I use if there are several invoices?
Check each cost separately. A single demand can include some costs that are in time and others that are not.
Does the rule apply to ground rent?
No. Section 20B is about service charges. Ground rent has its own rules.
Does the 18-month rule change in 2027?
In England, from 1 April 2027 the written-warning exception is replaced by a "future demand notice" under the Leasehold and Freehold Reform Act 2024. The 18-month limit itself stays. The rules on what that notice must contain had not been set when this calculator was last updated. Wales is not affected.
This is information, not legal advice. The calculator applies section 20B to the dates you enter. It can't see your lease, the invoices or any letters you've had. For free, independent advice, contact LEASE (the Leasehold Advisory Service).