Jonas Peter Haraldsson, from Skärholmen in west Stockholm, said he planned to appeal the Swedish National Tax Agency's (Skatteverket) decision not to allow him to replace the name Peter with Hallå.
"It started as a bit of fun, since I have three daughters at home who begin every sentence with the word 'Hallå'. And besides, it's just the middle part of my name" he told The Local.
"But now it's a question of principle. After my application was turned down, I got to thinking: why should Skatteverket be able to decide over what I want to call myself?"
In its ruling, the tax agency said the name could not be approved because it might "cause offence and is likely to lead to discomfort for the bearer".
"Skatteverket is of the opinion that Hallå is not a first name; it is well known as a greeting and as such is not appropriate as a first name" the agency wrote.
Kenth Hammarström at Skatteverket explained that the agency was just following the letter of the law.
"In Sweden, unlike in a lot of other countries, we have legislation preventing people from using names that may cause offence. You can't be named after a swear word, for example, and Satan is out of bounds, as are individual letters of the alphabet," he told The Local.
Although not comparable with a dirty word or the forces of biblical evil, the name Hallå would not enter the pantheon of approved names unless a court ruled otherwise.
"It's simply not a free choice," said Hammarström.