We evolved these initiatives and increased our savings target to $500 million through 2021.
In 2021, we will continue to enhance our productivity and anticipate delivering approximately $160 million of incremental savings.
And with the DN Now transformation set to conclude by year-end, our restructuring payments will also come to end, with cash restructuring payments expected to be no more than $50 million this year.
The net result of our efforts will drive a strong sequential step up in free cash flow, which is anticipated to be in the range of $140 million to $170 million for the year.
Early deployments with legacy ATMs suggest that ACDE can reduce call rates by approximately 20%.
2020 was a very strong year for Diebold Nixdorf from a self-checkout shipments perspective as we delivered growth of approximately 90% in the fourth quarter and just over 2% for the full year.
The high service attach rates of approximately 90% is another reason to like this business.
We are currently deploying our Vynamic Payments platform at our first client, a top 10 global financial institution.
Despite the continued complexities of the COVID-19 pandemic, product orders increased 17% in the fourth quarter, with banking growth of 34%.
At the same time, we enhanced our execution of the DN Now transformation initiatives and delivered approximately $165 million against our savings targets during the year.
With respect to free cash flow, our fourth quarter results of $186 million was the strongest we've experienced in eight quarters, fueled by solid profitability and strong collections.
For the full year, the company generated $57 million in free cash flow, which exceeded our outlook by $27 million.
Against this backdrop, our 2021 outlook is for revenue of approximately $4 billion to $4.1 billion or 3% to 5% growth, adjusted EBITDA of $480 million to $500 million which translates to 6% to 10% growth, and significant free cash flow growth to a range of $140 million to $170 million.
Strength in product orders during the quarter drove our product backlog 23% higher versus the prior year.
In Poland, we procured a $7 million contract for self-checkout products and Vynamic iScan software licenses with another large grocery store.
In Saudi Arabia, we booked an order with a top three bank to refresh 1,800 ATMs with DN Series.
We also booked a new logo in Egypt for 500 DN Series in support of this bank's expansion initiatives.
In the Netherlands, we secured two new contracts valued at approximately $11 million to provide DN Series ATMs and indoor Lobby cash recyclers.
In the Americas, we expanded our existing partnership with Citibank for additional DN Series ATMs, a full Vynamic software suite and maintenance services across 15 countries, which will help standardize the customer experience, while reducing complexity, cost and security risk.
We also won a new contract to install 1,000 new DN Series cash recycling modules and our IoT-enabled All Connect Data Engine with the largest private bank in Brazil.
During the first quarter of 2021, we are seeing continued success with an initial order for cash recycling DN Series units and maintenance services at a top 10 financial institution in the United States.
We reported sequential growth in the third and fourth quarter of more than 10%.
Our fourth quarter revenue was about 5% better than our recent outlook.
Full-year revenue of $3.9 billion declined by 11% as reported and 8% when one removes the effect of divestitures and currency fluctuations, with most of that decline attributed to COVID delays.
Adjusted EBITDA increased 13% to $453 million for the full year.
Our adjusted EBITDA margin of 11.6% increased by 250 basis points versus the prior year.
And I previously mentioned our strong fourth quarter free cash flow performance and now total $57 million for the year.
These incremental projects will yield longer-term benefits, so there is no change to our cumulative DN Now savings target of $500 million through 2021.
For the quarter, we had spent $72 million of restructuring and transformation expenditures and paid approximately $60 million in cash.
We are targeting a maximum of $50 million for these cash payments for 2021.
During the fourth quarter, non-routine expenses were approximately $8 million and we expect these adjustments have largely concluded, with the exception of divestiture-related costs.
Fourth quarter revenue of $1.1 billion declined 2.5% after adjusting for foreign currency and divestitures.
Foreign currency was favorable by approximately $18 million and divestitures were unfavorable by $36 million.
Our revenue variance was primarily due to unplanned delays of approximately $40 million, largely driven by the pandemic.
We delivered product revenue growth of 1% versus the prior quarter, showing a strong rebound from COVID-19, and we are encouraged by robust order entry growth during the second half of 2020, supporting a stronger rebound ahead.
Continued strong gross margin results in the quarter were offset by the revenue decline, resulting in a $7 million decline in gross profit versus the prior-year period.
Progress on our services, modernization and software excellence initiatives drove a 50 basis point increase to total gross margin versus the prior quarter.
Software margins expanded 850 basis points, services expanded 120 basis points and products declined 230 basis points due to a less favorable geographic customer mix in our banking segments.
Operating profit increased $4 million or 4% versus the prior quarter, while operating margins increased 80 basis points to 9.5% for the quarter.
We delivered adjusted EBITDA of $128 million, which exceeded our prior outlook by $13 million.
Adjusted EBITDA margin expanded 20 basis points year-over-year to 11.6%.
Fourth quarter free cash long was $186 million.
The upside to free cash flow versus our model was higher profitability and significantly stronger cash collections, which dropped our days sales outstanding by 8 days sequentially.
On slide 10, Eurasia Banking revenue for the quarter increased 1% to $419 million after adjusting for $36 million from divestitures, net of a $20 million benefit from foreign currency.
Total gross profit was down $4 million year-over-year, reflecting a stable margin on lower revenue.
Moving to slide 11, Americas Banking revenue of $375 million declined 7% versus the prior quarter, excluding a $13 million foreign currency headwind, primarily reflecting non-recurring projects in North America as well as COVID-19 related project delays.
Segment gross profit of $100 million was down $8 million year-over-year due to the revenue decline, partially offset by gross margin expansion of 90 basis points due to our DN Now transformation initiatives and a more favorable product mix.
On slide 12, retail revenue of $312 million was 1% lower year-over-year after adjusting for a $12 million foreign currency benefit.
Gross profit increased to $73 million during the quarter as our mix of products was more favorable due to the rising self-checkout shipments and our DN Now initiatives positively impacting services and software margins.
Retail gross margin expanded by 80 basis points during the quarter.
At the end of 2020, the company's net leverage ratio of 4.4 times was unchanged from the end of 2019 as the increase in EBITDA and our positive free cash flow was offset by payments associated with our debt refinancing, M&A activities and an unfavorable exchange rate on foreign net debt balances.
We expect to use free cash flow to pay down debt and we're targeting a reduction in leverage ratio to less than 3 times net debt to adjusted EBITDA by 2023.
The tax principals provide products and related support to distribution subsidiaries in approximately 60 countries.
Due to high restructuring, transformation and interest payments, the combined tax principals reported a pre-tax loss, but paid approximately $7 million of income taxes due primarily to tax loss pertaining to the US foreign source income alignment, or in tax jargon, if you prefer that, the Global Intangible Low Tax Income, GILTI provisions and Subpart F provisions of the US tax code.
On a collected basis, distribution subsidiaries paid approximately $30 million in cash income taxes during 2020, bringing total company cash income taxes to approximately $37 million.
Taking into account all the factors listed on this slide, we expect cash tax payments in 2021 will be approximately $35 million, while targeting an effective tax rate of 25% to 30%.
We are expecting revenue in the range of $4 billion to $4.1 billion, which translates to a 3% to 5% growth.
Divestitures, which have already been completed, are expected to result in a headwind of approximately $50 million to services revenue, with the majority impacting our first half results.
Our adjusted EBITDA range is $480 million to $500 million or 6% to 10% growth.
Key contributions are expected from top line growth and $160 million of DN Now savings, primarily from higher mix of DN Series, software excellence and greater efficiencies from our service organization and All Connect Data Engine.
Offsetting these benefits are approximately $40 million of incremental growth investments in growth areas, which Gerrard discussed today, a $40 million reversal of one-time savings and services gross margin benefits, which occurred in 2020, and investments we are making in people, which primarily relate to the timing and magnitude of merit increases, and also inflation.
For operating expenses, the net effect will be approximately $20 million of higher expenses in 2021 versus 2020.
In terms of seasonality, we expect our first half will account for approximately 45% of annual revenue and approximately 40% of annual adjusted EBITDA.
We expect to generate $140 million to $170 million in 2021, representing an EBITDA to free cash flow conversion rate of approximately 30%, up from 12% in 2020.
We expect net working capital to be a $50 million source of funds in 2021 as accounts receivable DSOs and inventory investments normalize from COVID-19 impact.
$170 million in interest payments; $50 million of restructuring payments; $85 million of capex and software development payments; and 75 million from cash taxes, pension and other items.
Starting with revenue, we are targeting annual organic revenue growth of 2% to 4% through 2023, supported by the areas which I discussed earlier.
We also expect to deliver ongoing operational efficiencies and gross margin expansion in our services business through widespread deployment of our All Collect Data Engine, which underpins our gross service margin target range of 32% to 33%.
Collectively, these factors contribute to an adjusted EBITDA target for 2023 in excess of 13%.
Our plans call for increasing this ratio from 12% in 2020 to approximately 30% in 2021 and approximately 50% in 2023.
We expect cumulative three-year levered free cash flow to exceed $600 million.
Furthermore, we believe the company can generate a return on invested capital of greater than 20%.
As we increase our profitability and use excess cash to pay down debt, we expect to reduce our leverage ratio to less than 3 times net debt to trailing 12 months adjusted EBITDA.
Since 2015, we have systematically reduced our carbon emissions by 16,500 metric tons, and we report our results in the Carbon Disclosure Project.
As a global company, operating with customers in over 100 countries and employees in more than 60 countries, we also take our role as a global citizen seriously.
As part of our global citizenship actions, the Diebold Nixdorf Foundation has committed to $0.5 million to expand financial literacy in underserved populations through an organization called Operation HOPE.

Summary:
Against this backdrop, our 2021 outlook is for revenue of approximately $4 billion to $4.1 billion or 3% to 5% growth, adjusted EBITDA of $480 million to $500 million which translates to 6% to 10% growth, and significant free cash flow growth to a range of $140 million to $170 million.