In order to change to an old family name, it must have been passed down directly in your family for at least two generations. Further, it must have been used within the last four generations (counting from your parents).
In some cases, you may need to turn to the regional state archives to get an extract from the birth and baptism book.
Johan Frisk wants to change his surname, to his maternal grandmother's maternal grandmother's maiden name – Grip. Johan's maternal grandmother's maternal grandmother got married in 1881 and her parents were also called Grip. In Johan's case, the conditions for taking the surname Grip have been met.
Johanna Svensson decides to change to her paternal grandmother's mother's maiden name, Sköld. Johanna's paternal grandmother's mother got married in 1895 and her parents were also called Sköld. In Johanna's case, the conditions for taking the surname Sköld have also been met. Johanna is married, but her husband has not changed surname previously. Therefore, when Johanna gets her application approved by PRV, her husband can take the new surname without paying a fee by applying to the Swedish Tax Agency.
Your partner can have the right pass on the family name
If your husband or wife is included in the application to PRV, he/she also has the right to pass on the old family name, even if the marriage ends. That right does not apply if he/she changes to the name through the Swedish Tax Agency.