The couple explained to Mumsnet that they would be planning "a large event with many guests" but that the ceremony would not be legally binding.
"Because of this, DP (dear partner) and I are heading to our local registry office next week to do the legal part of the marriage," they explained.
"We don't want this formality to overshadow our wedding next month, which we consider the actual day we marry.
"So, for the registry wedding, we aren't having guests (just two acquaintances as witnesses), no vows or ring exchange, and we'd planned to work that day as usual (it's over lunchtime)."
Their friends and family were baffled at their decision to get married on their lunch break and not just take the whole day off to celebrate.
"But to me, this day is merely a legal formality," they wrote, adding that their mother insists "it will be a special and emotional day regardless, and that it would be silly not to acknowledge it as we'll never get that day back."
Asking Mumsnet users for advice, many tended to agree with their mother, suggesting they should just take the day off.
"I agree with her, I'd go out for a lovely lunch together," one wrote.
"I also agree with her; even if you just go for some lunch and spend the afternoon together, it's still a special day," another said.
"It is only a legal formality, but at the same time, it is your legal wedding. I'd definitely go out for a nice lunch afterwards," added another.
"If you can't take a day of leave to celebrate the day you get married, what do you use it for? Even if you just consider it a formality, what if there's a delay? You don't want to be rushing back to work," another wrote.
"To me the legal formality is the wedding. That's the date on your marriage certificate, the one you count anniversaries from etc. I'd say it's more important than the blessing and the party," another pointed out.
However, one commenter shared they had done a lunch break wedding with no regrets.
"We got married on my partner's lunch break with a couple of colleagues for witnesses - no regrets! The emotional bit for us was the ceremony with our friends and family, which was a few weeks later," they explained.
