I posted the wrong total. How do I fix it?

Withdraw the bill with a reason and post it again with the right figure. If a share is already on a charge that has been presented for payment, credit that tenant instead.

From the guide Utility Billing: Splitting a Building’s Utility Bill Between Its Units.

Withdrawing a bill

• Open the bill and choose Withdraw, with a reason. Every share still on a charge nobody has started collecting is taken off, and each tenant is emailed why.
• A share on a charge already presented for payment — being paid, paid, or being retried — cannot be taken off, because the tenant may be paying it at that moment. Seayora refuses the withdrawal and names those charges; credit the tenant instead.

Read the whole guide: Utility Billing: Splitting a Building’s Utility Bill Between Its Units

More questions about Utility Billing: Splitting a Building’s Utility Bill Between Its Units

• Can I bill a utility the lease does not mention?
• What happens to a vacant unit’s share?
• Why was my share added to next month’s rent and not this month’s?
• Why can I not post the same bill twice?
• Why does Seayora say a unit was already billed for these days?
• Is the bill I read kept anywhere?