Brendan T. Cavanagh
Executive Vice President and Chief Financial Officer at SBA Communications
Thanks, Mark. Good evening. SBA finished 2021 with our best quarter of the year. The quarter included financial and operating results ahead of our expectations and continued strong momentum into 2022. Total GAAP site leasing revenues for the fourth quarter were $539.4 million and cash site leasing revenues were $529.8 million.
Foreign exchange rates were generally in line with our previously forecasted FX rate estimates for the quarter. They were a headwind though on comparisons to the fourth quarter of 2020 negatively impacting revenues by $2.1 million on a year-over-year basis. Same tower recurring cash leasing revenue growth for the fourth quarter, which is calculated on a constant currency basis was 4% over the fourth quarter of 2020, including the impact of 2.7% of churn.
On a gross basis, same tower growth was 6.7%. Domestic same tower recurring cash leasing revenue growth over the fourth quarter of last year was 6.3% on a gross basis and 3.9% on a net basis, including 2.4% of churn. Domestic operational leasing activity or bookings representing new revenue placed under contract during the fourth quarter was at its highest level of the year. This was the highest quarterly level since 2014.
Even with this high level of execution, we continued to replenish our domestic new lease and new amendment application backlog, which remained very healthy at year-end. These backlog support our expectations for continued strong domestic operational leasing activity throughout 2022.
During the fourth quarter, amendment activity represented 48% of our domestic bookings with 52% coming from new leases. The big four carriers of AT&T, T-Mobile, Verizon and DISH represented 96% of total incremental domestic leasing revenue signed up during the quarter.
In the fourth quarter reported domestic site leasing revenue was slightly impacted by the timing of revenue commencements versus our internal estimates, primarily with regard to new dish leases. This is a timing issue only as the number of leases executed exceeded our expectations. During the quarter, we also had slightly less domestic churn than our internal estimates due to delays in timing versus our prior estimates.
Internationally, on a constant currency basis, same Tower cash leasing revenue growth was 4.3% net including 4.4% of churn or 8.7% on a gross basis. International leasing activity increased again and was at the highest level of the year. As anticipated, the impact of international churn increased in the quarter as we began to see greater impacts from carrier consolidations and other networking contract modifications in Central America, although there were some churn timing delays that resulted in slightly lower reported international churn for 2021 that we previously forecasted.
In Brazil, our largest international market, we had another solid quarter of leasing activity. Gross same tower organic growth in Brazil was 9.8% on a constant currency basis. During the fourth quarter 84.9% of consolidated cash site leasing revenue was denominated in US dollars. The majority of non-US dollar denominated revenue was from Brazil, with Brazil representing 11.3% of consolidated cash site leasing revenues during the quarter and 8.1% of cash site leasing revenue excluding revenues from pass through expenses.
Tower cash flow for the fourth quarter was $434.1 million. Our Tower cash flow margins remained very strong with a fourth quarter domestic Tower cash flow margin of 85% and an International Tower cash flow margin of 70.1% or 91.6% excluding the impact of pass-through reimbursable expenses,
Adjusted EBITDA in the fourth quarter was $409.1 million. The adjusted EBITDA margin was 69.8% in the quarter. Excluding the impact of revenues from pass through expenses, adjusted EBITDA margin was 74.5%. Approximately 97% of our total adjusted EBITDA was attributable to our tower leasing business in the fourth quarter. During the fourth quarter, our Services business produced record results for the third quarter in a row with $55.9 million in revenue and $12.9 million of segment operating profit.
Notwithstanding these record results, we were able to completely replenish our Services backlog, finishing the year at an equal level to our company all-time high backlog from September 30th. Based on this backlog and the continuing high activity levels by our customers, we are projecting another very strong contribution from our Services business in 2022.
AFFO in the fourth quarter was $310.8 million. AFFO per share was $2.81, an increase of 13.3% over the fourth quarter of 2020 on a constant currency basis. During the fourth quarter, we continued to expand our portfolio, acquiring 59 communication sites for total cash consideration of $38.4 million. We also built 88 new sites in the quarter, including our first seven sites built in our new market, the Philippines. Jeff will touch on our expansion into the Philippines in a moment.
Subsequent to quarter-end, on January 4th, we closed on our previously announced deal to acquire towers from Airtel Tanzania. This transaction added 1,445 sites to our tower portfolio at a cash purchase price of $176.1 million and the impact of this transaction is fully included in our 2022 full year outlook. Additionally, subsequent to year-end, we have purchased or under agreement to purchase 371 sites in our existing markets for an aggregate price of $137.1 million. We anticipate closing on these sites under contract by the end of the third quarter.
In addition to new tower assets, we also continue to invest in the land under our sites. During the quarter, we spent an aggregate of $13.6 million to buy land and easements and to extend ground lease terms. At the end of the quarter we owned or controlled for more than 20 years, the land underneath approximately 72% of our towers and the average remaining life under our ground leases, including renewal options under our control is approximately 37 years.
Looking ahead now, this afternoon's earnings press release, includes our initial outlook for full year 2022. Our outlook reflects a significant increase in organic leasing revenue contributions from new leases and amendments. This increased organic leasing contribution is largely due to the increased pace of new leasing activity, we experienced during 2021, as well as some contributions from anticipated continued strong organic leasing activity during 2022.
Our outlook for contributions from new leases and amendment is based in part on estimates of lease commencement timing with each of our customers and shifts in the timing of equipment installations may have minor impacts on these estimates as they did in the fourth quarter. We are also projecting increases in contributions from contractual escalations. Most of the increase is projected in our international markets where inflationary increases are expected to drive increased rental escalations.
In addition, our leasing revenue outlook contemplates increased impacts from customer churn in 2022, the primary increase is in connection with anticipated Sprint-related decommissioning. Our outlook incorporates a current estimate of approximately $30 million of churn in 2022 related to legacy Sprint leases and our previously provided estimates of aggregate Sprint related churn over the next several years remains unchanged.
Our total churn projections for 2022 are based in part on internal estimates of a variety of factors that can impact the timing of actual revenue seed states. To the extent that there are variances from these internal estimates, there may be impacts on our reported 2022 churn rate. However, any differences in reported 2022 churn from these variances is a timing issue and does not change our expectations for long-term aggregate churn.
In addition to Sprint churn, our outlook includes increased churn in our international markets, primarily due to carrier consolidation in Central America. Our full year 2022 outlook includes the projected impact of the Tanzania acquisition, but it does not assume any further acquisitions beyond those under contract today.
The outlook also does not assume any share repurchases, other than those completed as of today. However, we are likely to invest in additional assets or share repurchases or both during the current year. Our outlook for net cash interest expense and for AFFO do not contemplate any further financing activity in 2022. However, we will continue to look for opportunities to optimize our balance sheet and our cost of debt.
Finally, our outlook for AFFO per share is based on an assumed weighted average number of diluted common shares of $110 million, which assumption is influenced in part by estimated future share prices. We are very excited about 2022. Our customers are all very active and we expect to produce very strong results as we help them to achieve their network build-out goals.
And with that, I'll now turn things back over to Mark, who will provide an update on our liquidity position and balance sheet.
