re: incorrect dates on tenancy agreement

Tax Planning and Financial

I am contacting you on behalf of a letting agent we rented a property back out in July 2007 on a non managed basis, the landlord has rang us to advised the tenants have now left but he has notice our tenancy agreement has the incorrect dates, we have started the tenancy from July 2007 to December 2007, this must have been a printing error as tenancy should not of expired till January 2008. The tenancy does state the rent will be six equal payments at £550.00 not five, can the landlord pursue the tenants for this or claim back from us due to neglicence. We do not have a signed copy on file so cant see if the landlord signed it or we did it on his behalf although a copy would of been sent to landlord to check upon the tenants occupying, and the lady that issued the paperwork is no longer with the company.