Good day, ladies and gentlemen, and welcome to the Airtel Africa presentation for the year ended 31 March 2022. All participants are currently in listen only mode and there will be an opportunity to ask questions later during the conference. If you should need assistance during the call, please signal an operator by pressing * and then 0. Please note that this event is being recorded. I would now like to turn the conference over to Mr Segun Ogunsanya. Please go ahead, sir.
Thank you. Hello everyone and thank you for joining us on today’s presentation and conference call. I will first cover the highlights and then hand over to Jaideep who is going to take you through our financial results for the year. After that I will take you through some of the strategic and operational development before we then open the floor for your questions. If you turn to slide number three, it’s a summary of our performance. With our continued strong revenue growth, our underlying EBITDA margin expansion and our strengthened cash generation, we have not only delivered financially but we have also delivered strategically, operationally and sustainably, and I’m going to talk to these on slide number four. Financially I’m going to ask Jaideep to talk through the details, but at a very headline level we continue to deliver a very strong revenue growth, underlying EBITDA margin expansion, which is now at 49%, and very strong earnings per share growth. As we do this, we continue to strengthen our balance sheet and improve our leverage position, now 1.3x, at the same time reducing our foreign currency debt at HoldCo level.
These very strong financial improvements are an output of our continued strong operational developments as we continue to expand our customer base, grow our ARPU by driving usage, and invest in our network with almost 90% of our sites now on 4G. all both mobile money and data, continue to be growth engines, with mobile money transactions alone reaching $64 billion this year. Strategically, the highlight is our receipt of a full PSB license for us to develop our mobile money services in our largest operation, Nigeria. We have also brought in $550 million of investment into the mobile money business, we have bought out minorities in Nigeria, and we have completed tower sales in Tanzania, Madagascar and Malawi, generating proceeds of $284 million. In addition, we bought additional spectrum in Kenya and Malawi.
On sustainability, which has always been at the core of our business, we have fully articulated our strategy with ambitions, goals and commitments for our business, our people, our community and our environment. Sustainability now underpins our six-pillar corporate growth strategy. On slide number five we have shown how the business has delivered against six key objectives from mobile service revenue to dividends payout. And now you can see the tracker on how we delivered against all of these six key objectives. With this very brief introduction, I’m going to hand over to Jaideep to take you through our financial performance for the year. Jaideep, please.
Good morning and good afternoon to all of you. Let me start with the key financial highlights. On slide seven we have delivered a strong set of results for FY2022. We continued our revenue growth momentum and our EBITDA margin expansion. Full year revenue was $4.7 billion and underlying EBITDA was $2.3 billion. Revenue growth for the full year was 23.3% and underlying EBITDA growth of 31.2% in constant currency. Underlying EBITDA margin improved to 49% for the full year. That’s about 3% improvement from prior year.
Earnings per share before exceptional items almost doubled to 16 cents. Our balance sheet position has continued to improve and now our leverage ratio improved to 1.3 times from 2 times in the prior year. The board has recommended a final dividend of 3 cents per share. Therefore, the total dividend for the full year will be 5 cents per share.
Coming to slide number eight, revenue in Nigeria grew almost 28%, supported by both customer base growth of 5.8% and ARPU growth of 33%. Customer base growth in Nigeria was impacted by the NIN SIM regulation during the first half of the year but returned to growth in this region in the second half of the year, adding about 4 million customers during H2. Underlying EBITDA grew by 30% with a margin improvement of 114 basis points and the margin now stands at 55%. In East Africa revenue grew by more than 22% with an EBITDA growth of 32%. Underlying EBITDA margin reached almost 50%, an improvement of 331 basis points in constant currency.
In Francophone Africa the customer base grew by almost 16% and revenue grew by 17%. Underlying EBITDA grew 28% with an underlying EBITDA margin expansion of 337 basis points to 41%. Coming to slide number nine, performance of our key services, voice contributed to half of the total revenue and grew by 15%. Data contributed 32% and mobile money almost 12%. Both data and mobile money services are growing about 35%. As you can see, our voice revenue growth of 15% was driven by growth of both our customer base and ARPU. Similarly, our data and mobile money revenue growth of about 35% was driven by both customer base increase and ARPU growth. Data ARPU growth was mainly as a result of increased 4G penetration. And 4G data usage per customer increased to 5.5 GB per month, much higher than our total average data usage per customer of 3.4 GB per month. Mobile money ARPU growth of 12% was driven by growth of cash-in / cash-out transactions, merchant payments, P2P transfers and mobile service recharges. Coming to slide ten, this shows the incremental revenue contribution from our key services. Revenue in reported currency grew by 21.3%, while in constant currency growth was 23.3%. The differential was due to currency devaluation, mainly in Nigeria and Malawi, offset by appreciation in the Zambian kwacha and Rwandan shilling. All our key service segments of voice, data and mobile money contributed to the revenue growth.
Coming to slide 11, our underlying EBITDA grew by 29% in reported currency and absolute EBITDA for the year was $2.3 billion. Currency devaluation had an adverse impact of $26 million due to devaluation in Nigerian naira and Malawian kwacha offset by appreciation of Zambian kwacha and Ugandan shilling. The underlying EBITDA margin improved to 49%, an increase of 296 basis points in constant currency.
The improvement in margin was led by both revenue growth and improved operational efficiencies and disciplined cost control. EBITDA flow through for the period was more than 60% during the last financial year.
Coming to slide number 12, our mobile money customer base grew by almost 21% mainly in the East African market. Mobile money customer base penetration reached 20.4%, an increase of 2%. The total transaction value increased to more than $64 billion, driven by an increase in usage per customer by almost 14% and also customer base growth of 20%. Underlying EBITDA was $270 million, growing by 38% in reported currency and by 34% in constant currency with an EBITDA margin of nearly 49%. Coming to slide 13, our cash flow generation for the full year was $622 million, largely as a result of our improved EBITDA performance and higher intangible capex in the prior year, partially offset by increased cash taxes resulting from higher operating profit.
Slide 14, our capital allocation policy remains unchanged. As mentioned earlier, our priority is to invest in the business and at the same time continue to aim at further strengthening the balance sheet. Capex for the full year was $656 million, in line with our guidance. Capex guidance for the next year is slightly increased to now between $700 million and $750 million, including the cost of rolling out our PSB operation in Nigeria.
Our leverage ratio improved to 1.3 times from 2 times in the prior year. During the year we repaid $915 million of bonds in May 2021 and in March 2022 we repaid $505 million of bonds a year earlier than their March 2023 redempt