Culiacan, Mexico - In 1970, Enrique Coppel Tamayo introduced a credit card that allowed his working-class customers to buy clothing and furniture at a handful of small retail stores he owned in Culiacan, Mexico.

Four decades later, his five billionaire sons have leveraged that idea into a countrywide network of 1,000 emporiums, where low-income shoppers buy goods such as smartphones, washing machines, and Lacoste perfumes on credit. They often opt to pay interest rates of as high as 60 percent - more than 13 times the central bank’s benchmark - to stretch their purchases over multiple installments.

Closely held Coppel SA generates $4.6 billion in annual sales and has the widest profit margin of any major Latin American retailer. Through their holding company, Grupo Coppel, the brothers - Agustin, Enrique, Ruben, Alberto, and Jose Coppel Luken - also have interests in a bank, a retirement-fund manager, and real estate. Together, they control a combined fortune worth $15.9 billion, according to the Bloomberg Billionaires Index. None of them has ever appeared on an international wealth ranking.

"They’re less visible than a comparable company on the exchange," said Miguel Guzman, associate director for Latin American corporate debt for Fitch Ratings in Monterrey. "But they shouldn’t be underestimated. They’ve realized that the low end market doesn’t mean that the people don’t want good service, good products and all of that."

With Mexico’s economy rebounding from the 2009 recession, and unemployment declining, the country’s consumers have more cash to spend on household goods. Coppel’s department stores in Puerto Vallarta and across the country, give the poorer among them the chance to buy a sofa-bed or an iPhone in small payments over six to 18 months. The Coppel empire has expanded despite the surge in violence in their native state of Sinaloa, home to one of Mexico’s most violent cartels.

In a November 13th telephone interview, Agustin Coppel, the 51 year-old current chairman and chief executive, said he disagrees with the calculation of his family’s net worth. He declined to elaborate, and turned down additional interview requests.

Coppel’s founder, Enrique Coppel Tamayo, passed his shares on to his five sons years before his death in 2007, said Alberto Martinez, a company spokesman. As of 1999, Agustin had 17% of the company, Enrique held 25%, Ruben had 20%, and Alberto Coppel owned 19%, according to a convertible bond prospectus published at the time. Jose’s 19% stake is accounted for by holdings in his wife’s name and an anonymous fund. The family declined to comment on whether the stakes have changed since then.

The company’s retail operation generated $60.8 billion Mexican pesos ($4.6 billion) in sales, and their 14% profit margin is the biggest of any Latin American retailer with a market value of at least $1 billion. Its closest competitor is Grupo Elektra SAB, controlled by fellow Mexican Ricardo Salinas, who holds eighty-third place on Bloomberg’s index with a fortune of $10.7 billion.

Agustin, the youngest Coppel brother, is worth $2.7 billion, while Enrique, the oldest, is worth $4 billion. Jose and Alberto are both worth around $3 billion, while Ruben’s fortune is $3.2 billion.

The retailer had the equivalent of $2 billion in outstanding loans to customers at the end of the third quarter. Customers were late on 26% of that amount, according to the company.

Coppel’s retail operation is valued at $14.4 billion, and BanCoppel SA, the family’s bank, generated a profit of $26.5 Million in the 12 months ending September 30th.

The family’s retirement fund unit, Afore Coppel SA, managed at least $60 billion pesos as of September and charged an annual fee of 1.59%, according to the Mexican retirement-fund agency, known as Consar. The resulting annual revenue is $72.2 million USD.

In 2011, Coppel stores paid $1.4 billion pesos in rent for the properties owned by the brothers’ Sakly SA. That company is valued at $450 million.

The family reinvested all of the retailer’s profits from 2002 through 2008, according to a statement with Mexico’s exchange. Based on reported dividends since then, after subtracting reinvestments in their bank and accounting for market performance, the brothers probably control a combined investment portfolio of more than $275 million.

Roots

The Coppel empire traces back to the 1930s, when Enrique Coppel Tamayo, a descendant of Polish immigrants, started a gift shop in the coastal Mexican town of Mazatlan with a $5,000 peso loan from his mother.

In 1941, he moved his business to nearby Culiacan, capital of Sinaloa. He traveled to Dallas to buy goods, branching out into foodstuffs, bicycles, furniture, and electronics. Early on, he started extending credit to his customers, who were often poor. That model still sustains the company today. In 1970, he created the Coppel credit card for purchases at his stores.

In the 1980s, with a dozen stores built around Culiacan, he passed the reins to his oldest son, Enrique Coppel Luken, who expanded to cities across Mexico, while also broadening their product offering. By 1990, his son had grown the company to 30 stores; by 2001, the family had 143 store, including the ones in Puerto Vallarta.

The patriarch died in 2007. The next year, Agustin took the helm of the retailer so that Enrique could focus on the retailer’s international expansion and their recently acquired financial interests.

Since then, Coppel has opened eight stores in Brazil and another eight in Argentina. Earlier this month, they opened their 1,000th Mexican store in Teotihuacan. Much of the family is still based in Culiacan, where the company is headquartered.

When contacted by phone on November 14th, a worker at a Coppel store in Atizapan de Zaragoza, near Mexico City, said that the company's Coppel card allows a customer to purchase an electric oven or furniture in biweekly payments over 12 months at a 33 percent annual interest rate, or over 18 months at a 60 percent rate.

“Change has been a constant at Coppel,” Enrique Coppel Luken once said. “But also the constant effort to really put into practice - on the sales floor, in our contact with the customer - everything we see that will help us attend to the customer better.”