Ticketek is the official booking agent for the venue and were charging service fees for tickets that were sent to attendees, or were picked up at the venue on the day.
Fees ranged from $5.50 to $16 per booking and the Christchurch City Council is offering refunds for anyone charged, saying it was a free public event and there was never any intention for bookings to carry a cost.
It said of the less than 30 people charged the fees, only one had applied for a refund so far.
CCC civic and international relations manager Matt Nichols estimated more than 1050 people attended.
"There were approximately 750 invited guests in attendance - bereaved families, those who were injured, Muslim community members, dignitaries," he said.
"And 412 tickets sold to the general public.
"People were also encouraged to join in through the livestream, and at 9am Monday morning, the service had been viewed 2978 times."
The Herald attended the service and counted about 150 people in the public area.
Nichols said the service was jointly led by the local Muslim community, Christchurch City Council standing with Ngāi Tūāhuriri as mana whenua, and the Government.
"We have had overwhelmingly positive feedback about the service, particularly from those most affected by the attacks and members of the Muslim community.
"There are multiple factors influencing people's decision to attend or not attend an event like this."
The service was set to start at the same time as the America's Cup and just hours before the Crusaders played the Chiefs in Christchurch.
Christchurch Mayor Lianne Dalziel told Newstalk ZB's Chris Lynch she was happy with the service.
"I was incredibly moved by the addresses from representatives of the Muslim community," she said.
"I thought they were just such powerful addresses.
"I was really proud of them, I thought they were really courageous."
Speakers included Kiran Munir whose husband Haroon Mahmood was killed in the attack on March 15, 2019, Maha Elmadani whose father Ali Elmadani was murdered, survivors Temel Atacocugu - who was shot nine times on the day - and Faisal Sayed.
The Governor-General and Prime Minister also spoke.
On March 15, 2019, a gunman stormed into the Al Noor Mosque and then the Linwood Islamic Centre and opened fire on men, women and children who were at Friday prayers.
By the end of his rampage 51 people had suffered fatal gunshot wounds and a further 40 were injured.
The gunman later pleaded guilty to 51 counts of murder, 40 of attempted murder and one count of terrorism.
He was jailed for life, with no possibility of parole.
Today's service was scheduled to go ahead in March last year to mark the first anniversary of the massacre, but was cancelled due to Covid-19.
