You can issue invoices even after leaving pixiv Sketch.
Please contact us via the contact form with the following information.
1) Addressee of the invoice (Qualifying Invoice Issuer registered name)
2) Qualifying Invoice Issuer registered number
3) The payment month for which you would like to issue the invoice
4) The type of invoice you would like to issue (Shoutout invoice or Reward transfer fee invoice)
5) pixiv user ID and registered e-mail address for the account where the payment was made
▼What is a user ID?
https://www.pixiv.help/hc/articles/235583588
* Invoices can only be issued for one month at a time. (Even if you request invoices for multiple months, they will be sent out as separate invoices for each month).
* The invoice for the current month may be issued starting from the fifth of the next month. Partial invoices may not be issued partway through the month.
* Invoices may only be issued by the taxable entity.