Sim proposed in June 2016, and the couple were married in New Zealand last March.
"As difficult as it was, we maintained a long distance relationship and even planned our wedding from opposite ends of the world," he said.
But for the couple, it was also the start of their struggles proving to Immigration that their relationship is genuine and stable.
Immigration New Zealand has confirmed that Tucker's application for a work visa-partnership had been declined because it was not satisfied that the couple were living together in a genuine and stable relationship.
Tucker first applied for the visa in April last year, but was told the evidence provided was insufficient. He was instead granted a 9-month visitor visa so they could stay together and prove their relationship was "genuine and stable".
"While it has been great to have been together at this time, being on a visitor visa meant Zach is unable to work, so we are surviving off my wage alone," Sim said.
They reapplied in October, but after six weeks were told they needed to provide even more evidence.
"It still wasn't made clear exactly what more evidence needed to be provided, or how much would be sufficient," Sim said.
So they sent a "whole bunch more" including bank statements, photos, letters of support.
Just after Christmas, Tucker received a letter saying his application had been denied on the grounds there was insufficient evidence.
Immigration New Zealand operations manager Tim Shepherd said the issue the agency had was in relation to the duration of time that the couple had been living together.
"Although Zachary stated that he had been living with his partner for six months, the majority of the evidence that was supplied centred around the period of when they first moved in together at the beginning of the relationship, rather than showing consistency throughout the six months," Shepherd said.
He said to be eligible for a partnership-based visa, couples needed to be together long enough to enable sufficient evidence to be submitted to satisfy an Immigration Officer that they are living in a genuine and stable relationship.
"The onus is on the applicant to provide sufficient evidence with their visa application to demonstrate that they meet the relevant requirements," Shepherd said.
"In the absence of such evidence, there is no option but to decline and application."
But Sim said it was unfair that it was left to the discretion of deciding what's "enough" is left to individual officers.
"We haven't been told exactly what it's needed for them to recognise that our relationship is in fact genuine and stable," Sim said.
Tucker, who grew up in Arkansas, said the uncertainty has been stressful and frustrating.
"I haven't been out of work this long, ever, and I just want to be financially independent again," said Tucker, who's visitor visa runs out on Feb 20.
"It stressful, and I find it really frustrating of just waiting around and not knowing what the future holds."
The couple have tried to make an appointment to meet the Immigration officer in person, but was told the agency didn't do meetings. They are appealing the decision.
OTHER COUPLES WHO STRUGGLED TO PROVE THEIR LOVE
A Northland grandmother was twice refused visitor visas for her Tunisian husband who is 20 years her junior. Last month, Mary Diana Ben Ammar of Waima, near Kaikohe, had to sell her house and move to Tunisia because Immigration New Zealand did not believe their relationship was bona fide.
In 2015, A couple with an age gap of nearly 40 years won a lengthy battle with Immigration New Zealand to prove their love is true. Indian-born Balwinder Singh, 24, fought for three years to prove he is in a genuine relationship with his wife, 61-year-old New Zealander Glyn Kessell-Singh.
