If you edit contracts (eg. edit prices or add new products to the contract), you can invoice these changes with the "Contracy alterations" tool that can be found on the "Contracts" section. Contract alterations tracks mid-invoice-term changes in contracts which you can turn into an invoice.
On the row you can see the name of the customer and the contract, invoice term of the alteration, number of days and monthly change. If you click a single row, you can see a detailed view of the alteration.
If you click on top of the term, you can edit the time period from which the alteration is calculated. As a default, the start date is the day the alteration was made and the end date is the last day of the invoice term whose invoice has already been formed. If the change in prices or products has been agreed to begin before the change was done into Koho, changing the dates might be necessary.
Clicking the "Before" or "After" links opens a corresponding version of the contract, in case it is necessary to compare the previous and subsequent versions of the contract.
Invoicing a single alteration
Single alterations can be invoiced from the "Invoice" button on the row.
On the "Invoice alteration" window you can choose how the invoice change will be invoiced. You can either create a new invoice, add the alteration to a pending invoice or to an upcoming invoice term.
If you want to add the alteration to a pending invoice, select the "Pending invoice" option. A dropdown menu appears where you can see all invoices for the customer that are on the "Unapproved" stage. Select the invoice where you want to add the alteration.
If you want to target the alteration to an invoice term that is in the future, select the "Coming term" option. From the dropdown menu you can select the desired term.
After you have selected how you want to invoice the alteration, click the "Invoice" button. An edit form of the invoice is opened where you can make changes to the invoice. Read more about editing invoices from this article: 4.1.3 Viewing, editing and sending invoices.
Invoicing several alterations at the same time
If you want to invoice several alterations at the same time, you can do that by first selecting all the alterations you want to invoice. After this you can select if you want to create a separate invoice for each alteration (1 invoice / change) or create one invoice per customer (1 invoice / customer) that has all of the alterations. Finally click the "Invoice selected" button to create the invoices.
Note that if there are a lot of alterations to invoice, it might take some time to create the invoices.