US payments firm Square, which is worth an estimated $6 billion, is tipped to shortly file for an initial public offering (IPO).

There has been hoopla for some time about a possible IPO of the firm, headed by Jack Dorsey, but it now appears about to happen.

According to Reuters, the filing is “imminent”, meaning it could be a public company before the end-of-the-year holiday season. Earlier, Fortune reported that Square would file for an IPO within two weeks.

Square itself declined to comment.

Two months ago, Square filed for a so-called private IPO, which lets companies with under $1 billion in annual revenue make a filing and go through a SEC review without public scrutiny. After the review, if the company wants to continue with an IPO, it makes a public filing.

Square processed $30 billion in payments from its merchant customers in 2014, although the actual amount of revenue it generates from the process is considerably smaller. The firm has been attempting to upsell its customers on higher-margin additional services.