Upgrade sim-only account midway through the month

[m0nsterm4sh]

Hi,

Wanting to upgrade my sim-only pay monthly account with an 18 month deal.  My current month is paid for another two weeks. 

When I go to upgrade it says "If you confirm, your new tariff will start straight away".  What happens to the two weeks I've paid for on my last bill?  Is it calculated by the billing system or do I lose those two weeks?

Many thanks.

[MI5]

The New tariff charge is added pro rata to your bill which remains on the same date.

[jonsie]

It's adjusted on your next bill. The billing date remains the same @m0nsterm4sh 

[m0nsterm4sh]

Thanks for the quick reply.  I've placed me upgrade order.

Cheers

[jonsie]

Excellent @m0nsterm4sh 

[MI5]

Just did mine the other day again this year.
I do it regularly to get the deals 😁

[jonsie]

Yes I've changed twice this year, on the same tariff as your good self