A couple of considerations should be in place for the contribution process.
The first is setting your Prudent Reserve for your group.
Prudent Reserver from the AA literature:
“Most groups try to hold a certain amount of money in reserve. There is no predetermined amount for such a reserve, but most groups try to put aside enough money to cover at least one to three months’ operating expenses. The group itself usually determines the actual size and scope of the prudent reserve. Our experience shows that an accumulation of A.A. funds for unspecified purposes beyond a prudent level may divert a group’s attention from carrying the message to the alcoholic who still suffers. Groups with excess funds are encouraged to support other service entities.“
Excess Money Contributions:
The AA literature establishes guidelines for groups that have met their Prudent Reserve and how they can contribute to support AA as a whole. See the image below: