RRSP contribution limits are attached to you, not to your RRSP accounts.
Your combined contributions to both your own RRSP and your spouse’s cannot exceed your annual contribution limit and still qualify for a deduction.
Any amount over the limit will not qualify for a deduction.
For example:If you contribute $6,000 to your RRSP account and another $6,000 to your spouse’s RRSP account in a tax year where your contribution limit is $10,000, you can only claim an RRSP deduction for $10,000. The remaining $2,000 will not qualify for the RRSP deduction in the current year, but you may be able to carry that amount forward to a year when you don’t use all your RRSP contribution limit. Note that your spouse can contribute her annual maximum, so with the addition of your contribution, her RRSPs can grow over her personal contribution limit.