In some cases you can add manual one-time charges to customers but it depends on how the customer was created.
Customers created by Stripe, Braintree, Recurly, Chargify, or Paypal
It is not currently possible to directly add manual one-time charges to customers that were created using the above integration.
Please note that while it's not possible to add manual one-time charges for the above integrations directly through ChartMogul, it should be possible to do so through your external billing connector.
Customers created manually from the UI
Customers created by the Import API, Google Sheet, or an integration built with the Import API (Chargebee, GoCardless, iTunes Connect, Chargeover, PayKickstart, Vindi, BillForward, Cleverbridge, Zuora, WHMCS)
Since some integrations use the Import API, it is also possible to add one-time charges but please be aware that in the event of a re-sync these manually added charges will likely be lost since they exist only in Chartmogul.
If you need further assistance please contact us at firstname.lastname@example.org.