Section 13

A landlord client of mine instructed me to issue his tenant with a Section 13 notice to increase the rent.

No problem, all done and sent to the tenant, which she acknowledged.

The landlord has since decided that he didn’t increase it by enough and has asked me to “add another £50 to it”.

The notice was served in accordance with his instructions but the date for the new rent has not yet passed. I’m aware that the rent cannot be increase more frequently than once every 12 months, but if the increase hasn’t yet taken effect is this permissible?