Putting A S21 Into AST & Guarantor Copping Out

Hi. We have just taken a property back that has about £500 arrears. There is a guarantor. The property has been let for 10 months.

We routinely bind in a S21 notice to be signed at the start of the tenancy dated for the initial period expiry of 6 months.

The guarantor's solicitor claims that as we terminated the tenancy by notice and that the rent was up to date on that date, the guarantor has no liability.

However, vacant possession was not granted on the day of the notice expiry, indeed the tenants remained at the property happily paying their rent until last month.

We would contend that the ast continued up to the point that vacant possession was granted and that the guarantor's liability continues up to the point that the final account is discharged.

What is your view of serving a S21 at the start of the tenancy and when the guarantor stops being liable for any debt?

Many thanks