T-Mobile delivered better-than-expected fourth quarter financial results on Thursday, with the wireless carrier touting record postpaid phone net customer additions and progress in post-merger synergies with Sprint.

T-Mobile said Q4 earnings were $750 million, or 60 cents per share, on revenue of $20.3 billion. Wall Street was looking for fourth-quarter earnings of 51 cents a share on revenue of $19.9 billion.

The carrier added 1.7 million net additions in the fourth quarter, along with 1.6 million postpaid. T-Mobile's postpaid churn came in at 1.03%, a slight increase for the company.

For the year, T-Mobile said non-GAAP earnings came to $2.65 per share on revenue of $68.4 billion. Analysts were expecting the company to report fiscal 2020 revenue of $67.7 billion on earnings of $2.70 per share.

By the numbers:

• The company ended the quarter and fiscal year with 102.1 million customers.
  
• For full-year 2020, total net customer additions were 5.6 million, with 5.5 million postpaid.
  
• T-Mobile added 824,000 branded postpaid phone net additions in Q4, and 2.2 million for the full year.
• Branded prepaid additions were 84,000 in Q4.
• Service revenue in the fourth quarter was $14.2 billion and $50.4 billion in full-year 2020, driven by the Sprint merger.
• T-Mobile said it covers 280 million people with Extended Range 5G.
• For 2021, T-Mobile said it plans to add 4 million to 4.7 million branded postpaid net customers. Adjusted EBITDA will be between $26.5 billion and $27 billion.

On its Sprint synergies, the company said it delivered $1.3 billion of synergies in full-year 2020, exceeding its guidance from last quarter. Meanwhile, customer network migrations began in the fourth quarter and more than 4 million have been completed, the carrier said. Once the migrations are complete, T-Mobile will fully decommission and shut down the Sprint network.

"These results show that we're pulling way ahead of the pack on what matters - overall 5G network performance - and executing to stay ahead," said Mike Sievert, CEO of T-Mobile. "2020 was quite simply our best year yet, with our highest ever total postpaid net additions of 5.5 million. Our team delivered – leading the industry on customer growth, while being the only major player to grow profitability as well, with our synergy-backed business model."

Shares of T-Mobile were down just over 1% after hours.