Is there a limit to how long an app can be free and then made paid?

With a PRO version of my app; i am planning on giving the app for free for the first 30 days and then a couple of days each month i will make it free.

Is there a limit to how long you can set your app for free before changing to a paid model? Is there anything else i should be aware of.

PS: When signing up for merchant through the dev console i am given an error and then redirected to my Google account overview. Anyone else experiencing this?

Thanks, James.

Google Play doesn’t allow changing from free to paid and vice versa.

Merchant only support some country and you can’t register if your country not support. And you can use In-App purchase with free app.

As Magnesus said, you can’t do that in Google Play, the only thing you can do with your PRO app is to lower the price for a while then rise it up again.

Although, what I’ve seen is that when a company wants to offer its pro app for free in Google Play, they publish it separately for free for a while, then take it off when the promotion is over but I don’t like that because users that downloaded the app with the promotion don’t benefit from future updates.

If you publish it as priced, you can later change it to free. Priced apps can be purchased and downloaded only by users who have registered a form of payment in Google Play.

Taken from the following page: Developer Console | Android Developers

It is nearly impossible to change your free app to paid app in Google play.
But some of the games in Google play store are free but has some in play costs which are optional.