How do I change the rent on a tenancy that's already running?

On an active tenancy, open Rent and choose Change the rent. Enter the new monthly amount and the date it starts. You can also record the date you served the notice, which keeps it with the tenancy rather than in a folder somewhere.

The date is the point of it. Nothing changes until then: rent collected before the date is the old amount, rent collected on or after it is the new one. A change you schedule months ahead simply sits there until its day.

• Your tenant sees the new amount and the date it starts on their own tenancy page, so they aren't relying on remembering a letter.
• A scheduled change can be cancelled any time before it takes effect. Once it's in force it stays on the record — a further change is how you move the rent again.
• Both the change and any cancellation are written to the tenancy's audit trail, with the old figure, the new figure and the dates.
• Rent can go down as well as up. A tribunal can determine a lower figure than the one proposed.

Worth knowing: Serve the notice first, then record it here. On an assured periodic tenancy a rent increase normally goes through the section 13 process, with at least two months' notice, no more than once a year, and not at all in the first year of the tenancy. The form you need is form 4A, on GOV.UK's assured tenancy forms page. Tenarize doesn't serve it — it records what you've done and collects the right amount from the right date.