Paying the Visa Fee and Scheduling For a K1 Visa Interview

Visa Fee Payment: 

K-1/K-2 visa applicants, who have been notified by the Embassy to prepare for their interview, must pay the visa application fee before they can schedule a visa appointment via the online appointment website or the Visa Information and Appointment Service. There are three ways to pay the K visa application fee:
a) Cash payment at any Bank of the Philippine Islands (BPI) branch;
b) Online payment bill option provided by BPI to their clients
c) Online payment through Bancnet.
<source>

I paid for the visa fee at the nearest BPI  branch near our home. The visa fee for K1 is $350 but you can pay using pesos. 

When I got there, I told the teller that I am paying for a US Visa fee, and she told me that I need to pay 6000 pesos (around that amount). I corrected her and told her that I should be paying around 15,000 pesos because I am applying for a K1 fiancee visa. Make sure you pay the right amount. She double checked her references and told me that K1 visa fee is equivalent to 15, 400 pesos. She asked for my passport and asked me to fill out the deposit slip. She asked me to write my passport number on the reference slip. :)

The MRV application fee is not refundable or transferrable to another person. You must schedule an interview within a year from the date you obtained your BPI fee receipt. If you do not schedule an interview within a year, you will not be able to use that BPI fee receipt – it will no longer be valid. The BPI fee receipt is deemed utilized once the interview takes place, and cannot be used to make a subsequent appointment. <source >

Scheduling Your Interview

You must wait for 4 hours from the time you paid your fee before you can schedule your interview. Whether you schedule your appointment online or contact our call center, you will need the payment code printed on your receipt. (This is the UID given to you at the Bank of the Philippine Islands or when you created your online profile.) You also need to have your passport number and your fee payment date in order to schedule your visa interview. <source>

So, I scheduled my interview online on
http://www.ustraveldocs.com/ph/ph-niv-appointmentschedule.asp.
Note: In applying for K1 visa, you do not need to fill out the DS-160 form online.