In August, the 35-year-old pop megastar announced, via Instagram, that the 36-year-old Kansas City Chiefs tight end popped the question.
But Sheeran - who has been best friends with Taylor since 2014 - didn't know about it until the news broke because he doesn't have a mobile phone.
Sheeran - who sees social media posts via a laptop and gets told about posts via his management - revealed to Access Hollywood.
"My way of viewing it is that me and Taylor are mates, and I will see her, and I saw her a week after that happened ...
"When I saw Taylor, we had a four-hour catch-up."
"I'm not self-conscious about my relationship with her. We've been friends for many years, we're super close, and we see each other when we see each other.
"And when we see each other, we lock back in to where we left off."
Months after their catch-up, Swift revealed why she didn't call him to share the happy news.
"I have a perfect explanation … he doesn't have a phone. I'm going through my texts and being like, 'Who have I texted within the last month in my life?' And he just wasn't there," she told Jimmy Fallon in October.
"You have to email him. If you want to set up a FaceTime, he has to find an iPad. They have to give it to him like he's a child that you give the iPad to."
She initially felt bad about not directly telling Sheeran about her engagement.
"This is one of my absolute favourite people on the planet.
"When the news came out, I was like, 'We forgot to call Ed! Oh, no!'
"He's like family. I love him, but he doesn't have a phone."
Sheeran said he ditched smart devices because he doesn't want them to run his life, and also he wants to be "present" for his wife Cherry, 33, and their daughters Lyra, five, and Jupiter, three.
"I've actually got rid of the iPad as well, I'm not on anything anymore ...
"I have someone who works on my management who finds stuff, sends it to me in one email, and I comment on everything. So I don't have to be chronically online, but I can have someone go, 'This is a funny video, check it out, comment on it'," he saisd.'
"I feel like devices are running people's lives, and I like opening a laptop, work, closing a laptop.
"I've got children, I've got a wife, I've got family, I want to be present, I don't want to be in the internet sphere 24/7.
"I know that it's culturally mental, but it's how I grew up as a kid, I wasn't in touch with anyone."
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