This Letter Writing Guide includes several sentences regarding payment or the sending of money. When writing to the Directorate of State Archives or to the local civil records office do not send money. They will bill you for their services which can be quite expensive. When writing to a local parish you may send money, if you wish. The safest way to send money is in the form of a New York bank draft which can be obtained at your local bank.
Some researchers send cash.
If you do not feel comfortable sending money through the mail you may indicate your desire to make a donation and ask how they would like to receive it. Money should not be sent to parishes as payment, but always as a donation. I live in the U.S.A., but my ancestry is from Poland and I would like to know more about my Polish ancestors. Mieszkam w Stanach Zjednoczonych, i jestem polskiego pochodzenia. I am preparing a history of my ancestors in Poland and need information from your vital records.