On the summary text in the portal, that says "You buy X units per month... This is within your tariff so should mean no charges next month/period.", adjust the wording to include a suggestion by how much to increase or decrease the tarrif by to avoid

I propose this improvement in relation to the recent broadband move I have had to do (between two properties) where metering was suspended and restarted part way through a full month. In this instance, you change the metering from being a 'month' to a 'period' (as things are not an exact month). This is fine, but the figures then calculated can become quite tricky to understand, and in my case, it was not clear by how much I had to increase my tariff by to avoid incurring extra charges. You already make the suggestion to increase tariff if the customer is likely to exceed their purchased units - it should be possible to advise them of how much to increase it by (in whole units). Similarly, it should also be possible to advise them of how much they can decrease their tariff to avoid being unnecessarily over charged on any given month/period.