Sends a letter through PixelLetter, either as ready made documents (absolute file paths, PDF preferred) or as plain text plus a recipient address that PixelLetter typesets. Optionally faxes the same document as well. Returns the result code and the transaction id.

Sends documents or plain text as a fax through PixelLetter, without posting a letter. Additional services such as registered mail do not apply to faxes.

Reads the stored customer data and the current credit of the PixelLetter account. Use it before sending to make sure the balance covers the order, error 021 means the credit is too low.

Cancels a submitted order by its PixelLetter order id, which is on the order confirmation e-mail. Only works while the order has not been printed yet, otherwise PixelLetter answers with error 055.

Sends documents to the PixelLetter invoice signing service (action 4) and optionally mails the signed PDF to the invoice recipient. The account needs electronic signatures enabled once in the customer area, otherwise PixelLetter answers with error 046.

Returns what the PixelLetter interface documents: action values, dispatch centres, additional service codes, allowed upload types, limits and the published error codes. Offline lookup, no API call.