It is recommended that you do not change banks - leave your money where it is until you speak with a loan officer or mortgage broker.

Lenders will probably ask that you provide bank statements for the last 3 to 6 months on any of your accounts, (checking, savings, money market funds, etc..) If you have a habit of shifting monies they may request a complete paper trail of all withdrawals and deposits for those accounts as well as cancelled checks, deposit receipts, and other information. This can be quite inconvenient and perhaps difficult to produce - not to mention time consuming!

It is a requirement on a majority of loans to completely document the source of all funds. Shifting your monies around will only complicates the whole process.