There is no reason of principle why a right of forfeiture arising from a failure to pay rent, cannot be waived in exactly the same way as a right of forfeiture arising from a breach of any other covenant in the Lease.
Russell LJ said: ‘The other argument put forward was that there can never be waiver of forfeiture for non-payment of rent by recognition of the continued existence of the Lease because, as has often been said, a right of re-entry for non-payment of rent is a mere security for the payment. I am not aware of any authority for this proposition, and I see no justification in principle for making this distinction between a default in an obligation to pay rent and any other obligation. Of course, rent may be demanded after the forfeiture days are passed, and, indeed, part payment accepted on account without waiving the forfeiture; this does not recognise the continued existence of the Lease beyond the date when that rent was payable. I refer in this connection also to the passage in Shepherd v Berger  1 QB 597, 599, which appears to me inconsistent with the proposition advanced.’
Lord Donovan. Russell, Megaw LJJ
 1 Ch 764
England and Wales
Cited – Central Estates (Belgravia) Ltd v Woolgar (No 2) CA 20-Jun-1972
Right to forfeit waived by rent demand
The landlords’ managing agents learned that the tenant had been convicted of keeping a brothel at the premises and served a section 146 notice intending to forfeit the tenancy. He told his staff and instructed them not to demand or accept rent. But . .
Lists of cited by and citing cases may be incomplete.
Landlord and Tenant
Updated: 12 April 2022; Ref: scu.568016