Dear …
We are in receipt of your request for a donation to __(Name of Organization)__. While we believe your cause is certainly worthwhile, regrettably, we are not able to offer financial support at this time. The portion of our budget allocated to charitable donations has already been expended.
Unfortunately, we are not in a position to overextend our current year budget spending. However, __(this/next)__ __(name of season or month)__, as with every year, we will be allocating funds in our new budget for various charitable donations. Perhaps you can contact us at that time to discuss a donation to your organization.
In the meantime, we wish you success with your current fundraising campaign.
Sincerely,