Please see the list of processing fees on the page Processing fees and payment methods.

You need to pay the processing fee when you submit the application. If you apply online, you can pay the processing fee before you submit the application.

You must apply for an extended permit before your current permit expires. If you stay in Finland without a residence permit you may be committing a violation of the Aliens Act and may be fined for it. The time you have stayed in Finland without a residence permit will not be counted towards your period of residence. We will not expedite the processing of a citizenship application when the applicant's residence permit is about to expire. The expiry of a residence permit is not a sufficient reason to expedite the processing of a citizenship application. 

You must have a valid passport during the entire time your citizenship application is being processed. Renew your passport if it is about to expire while your citizenship application is still pending. Please note that the expiry of a passport is not a sufficient reason to expedite a citizenship application. If you stay in Finland without a passport you may be committing a violation of the Aliens Act and may be fined for it.