Our cost of funding for this quarter held steady at 80% of the interbank deposit rate of Brazil aligning with our expectations. This consistency underscores our progress in harnessing the value of our robust liability franchise. We anticipate a slight decrease in the cost of funding next quarter, giving the seasonality observed in the final quarter of the year. Regarding Cuenta Nu in Mexico, at the close of the third quarter, we had accrued over a $150 million in deposits and amassed almost 2.4 million accounts. We believe the strong reception of our value proposition underscores our potential to further expand our deposit franchise model across Latin America. As mentioned previously, we also expect to launch our savings account in Colombia in the near future.
Our net interest income or NII reached $1.2 billion this quarter, marking another robust period of growth with an a 111% year-over-year increase. We believe this expansion can be attributed to the continued growth of our credit card and personal loans portfolio, which collectively have been the driving force behind the expansion of our NII and our net interest margin or NIM reaching new record highs. Our NIM achieved 18.8% this quarter, showcasing an increase of 7.7 percentage points compared to one year ago. Now let’s focus on the third pillar of our strategy, achieving a low cost to serve. We firmly believe that our most relevant and differentiating competitive advantage lies in maintaining a low cost to serve. As we have highlighted in previous discussions, our objective is to sustain a cost to serve at or below the $1 level for the foreseeable future.
In the third quarter of 2023, we once again successfully realized this goal with a cost to serve per active customer standing at $0.90. This figure currently remains virtually unchanged on an FX neutral basis compared to one year ago. All while our ARPAC increased by 18%. We believe this outcome underscores the robust operating leverage inherited in our business model. Our gross profit increased to a new quarterly record high, reaching $915 million marking an a 100% year-over-year increase. Our gross profit margin reached 42.8%, an increase of 1 percentage point sequentially and a 10 percentage point increase compared to the previous year. This data underscores the margin expansion that began in the third quarter of 2022. Notably, new achieved this result even in the face of higher credit provisions, a natural consequence of our growth in both credit card and personal loans as discussed in previous slides.
We maintain our commitment to operating leverage as a defining element of our strategy. The chart provided here underscores the ongoing enhancement of our efficiency ratio over time. In the third quarter of 2023, we reached a new all-time low registering an efficiency ratio of 35%, marking the 7th consecutive quarter of improvement. We firmly believe that this level of efficiency positions New Holdings as one of the most efficient companies in Latin America. While we have already achieved an impressive level of efficiency, we anticipate additional gains in operating leverage as we continue to scale through increased customer expansion, product upselling, cross selling, and the introduction of new features and products. Also, we believe there’s potential for increased leverage in the future, especially as our Mexican and Colombian geos, which are currently operating with losses, reach their inflection points.
Lastly, in terms of profitability, we are delighted to report yet another quarter of robust bottom-line performance. Our adjusted net income has reached at $356 million. Meanwhile, net income for the third quarter stood at $303 million. These strong and positive results serve as evidence of the effectiveness of our strategy and business model. While we are pleased with the results we have achieved thus far, it’s important to reinforce that our business is managed with a keen focus on long-term value creation. With this perspective, our strategy may entail additional short-term investments aimed at unlocking further long-term value creation opportunities. As I wrap up, let me provide the summary of the sustainable advantages across all 4 cost pillars.
In terms of cost to acquire, we successfully added more than 5 million customers this quarter while maintaining what we believe to be one of the lowest customer acquisition costs among consumer Fintechs and banks on a global scale. On cost to serve, we consistently kept it below the $1 threshold, which we estimate to be approximately 85% lower than that of incumbents. Our efficiency ratio is at 35%, which we believe makes new one of the most efficient companies in Latin America. Regarding cost of risk, we have effectively managed the risk within our credit portfolio, even in the face of a challenging backdrop. Outperforming competitors on an apples-to-apples basis in terms of delinquency rates. And finally, on the cost of funding front, we maintain our cost of funding at 80% of CDI, all while increasing deposit volumes substantially, thus closing the negative gap against in common banks and widening the positive gap over consumer Fintechs.
We are pleased with the results achieved this quarter, and we remain confident in our ability to develop and scale best in class products expand internationally and continue to operate at low costs. Now, I’d like to hand the call over to Youssef, our President and Chief Operating Officer, who will walk you through some of the key highlights of our asset quality.
