Aggressive cost-cutting returned American Express' Australian operations to profit in 2017.The latest financial accounts for American Express Australia Limited show the company turned a profit of A$75 million in the 12 months to the end of December - a big improvement on the $36 million loss recorded in 2016.A curious feature of the result was the comparatively high effective tax rate paid by the company on its gross earnings.The AMEX business coughed up $36 million on operating earnings of $111 million, giving it an effective income tax rate of 32.46 per cent.The company did not explain why it paid more than the standard corporate tax rate of 30 per cent.The accounts seem to indicate that AMEX defied the system-wide decline in credit and charge card spending last year caused by the Australian consumer's increasing preference for debit cards.AMEX's local arm had $3.58 billion worth of cardmember receivables and consumer loans on its December 31 balance sheet, up $530 million compared to the end of 2016.Most of the growth came through the credit card business, which expanded its contribution to receivables by 31 per cent to $1.15 billion.Despite the epic expansion in the value of the credit card portfolio, AMEX's charge card portfolio remains the mainstay of the Australian operation.The charge card business grew receivables by 10.8 per cent to $2.33 billion.Such growth reported by the company in its annual accounts seems inconsistent with data published by the Reserve Bank's Payments System Board, which indicate that AMEX and traditional charge card rival Diners' Club actually lost market share.According to the Reserve Bank data, the combined market share of purchases made on credit and charge cards issued by AMEX and Diners Club declined to 17.2 per cent in December last year from 19 per cent in the corresponding month in 2016.AMEX's revenue haul last year appears to support the findings of the RBA's number crunchers.Group revenue fell $18 million to $964 million.The profit turnaround seems to have been driven by a crackdown on costs that included 148 staff cuts.AMEX had 1154 employees on its books at the end of December - down 11 per cent from the start of the year.The company also sliced $100 million from its marketing budget, which guzzled $312 million for the year.There is some uncertainty hanging over the growth profile of the local credit card operation following decisions last year by ANZ and National Australia Bank to terminate distribution partnerships with AMEX.The full impact of the NAB pull out is likely to be felt this year because the phase out of AMEX cards issued by the bank was not completed until February.NAB's wind down of the AMEX arrangement resulted in the migration of customers to a Visa card product.