7. Receivables


	March 31,		December 31,
($ in millions)	2018		2017

Trade accounts receivable	$	1,332	$	1,206
Unbilled receivables		429		147
Less allowance for doubtful accounts		(10)		(10)
Net trade accounts receivable		1,751		1,343
Other receivables		339		291
	$	2,090	$	1,634

Unbilled receivables at March 31, 2018, include the effect of adopting new revenue recognition accounting guidance as of January 1, 2018. Further details of the new guidance and its adoption are included in Notes 2 and 4.

The company has entered into several regional committed and uncommitted accounts receivable factoring programs with various financial institutions for certain receivables of the company. The programs are accounted for as true sales of the receivables, without recourse to Ball, and had combined limits of approximately $800 million at March 31, 2018. A total of $211 million and $439 million were available for sale under these programs as of March 31, 2018, and December 31, 2017, respectively.