star trek - How did Worf pay for Yridian's information?

In the begining of "Birthright. Part I" episode (Star Trek Next Generation 6x16) an Yridian tells Worf, that he has a certain information,

that Worf's father is still alive (apparently not killed in Khitomer Massacre) and is held in a prison camp on Carraya IV.

Yridian is an information broker and agrees to reveal details (i.e. location) only for a price.

Worf agrees.

How or with what Worf would pay for this? There is no economic factor inside the Federation (no money is being used) and I don't recall anything, Worf would have on board Enterprise, that would have enough value for an information this kind.

Answer

Federation officers do seem to have credit accounts on DS9. Presumably they get a stipend from the UFP's own accounts to help them buy trinkets from the locals when visiting.

BASHIR: That better not be from a replicator, Quark.

QUARK: Chateau Cleon, twenty three oh three. I already put it on your account.

_{DS9 : The Adversary}

and

WORF: Our wedding plans have changed. We are getting married here on Deep Space Nine. And I want you to be my Tawi'Yan.

DAX: Sword-bearer. It's sort of like a best man.

ALEXANDER: Me? Really? Oh, that's great!

(He throws out his arms and hits a waiter's tray which crashes onto a table.)

QUARK (turning to Worf and Dax) I'll put that on your tab.

_{DS9 : You are cordially invited}

As a senior UFP officer, it also seems reasonable to assume that he would have the ability to simply write off certain expenses when they occur, in the same way that Beverly Crusher has the bolt of cloth charged to her account on the Enterprise in TNG: Encounter at Farpoint.

The Federation seem to almost treat latinum as monopoly money. Riker throws away 12 bars simply for hearing a rumour from Quark in TNG : First Born.