Here's the response I received when I SM'd them recently. I have two Chase cards and directed the question of an CLI to Chase/Amazon which is currently $12.5K.
... copy/paste
"Thank you for contacting Chase regarding your inquiry
about credit line increase on your account.
Kindly note, the option to request for a credit line
increase is not available online but can be requested via
e-mail or by calling our toll-free number located on the
back of your Chase credit card or at the number listed
below.
However, I will be happy to process your request for a
credit line increase. In order to do so, please reply to
this email with the following information:
* Gross Annual Income (Alimony, child support or separate
maintenance income need not be revealed if you do not want
to consider these as a basis for repayment. Gross Annual
Income is income that you are able to use for repaying
your debts. Examples may include income earned from
salaries, investments, rental properties, Social Security
benefits and retirement accounts.)
* Total credit line you are requesting (Current credit
line plus amount of requested increase.)
* We will also need your Housing Status of Own or Rent as
well as your monthly housing payment.
By submitting a request for a credit line increase, you
authorize Chase to obtain a copy of your credit report,
credit bureau history and any other information in order
to determine if the request can be approved.
After we receive this information, we'll process your
request and respond to you by email.
It is a hard pull on your credit report.
If you have any further questions, please reply using the
Secure Message Center.
Thank you,
Vandana Joshua
Customer Service Specialist
1-800-436-7927"
