Hi Vicky,
In my organization, volunteers support guided hikes alongside our paid guide staff, and we do allow them to accept tips since tipping is such a common practice in the guiding industry. Below is our language from our volunteer handbook, which matches our employee handbook. Please note that in our handbook, "staff" refers to both volunteers and paid employees, since we are all part of the same team.
"GRATUITIES
While our organization does not expect participants of our programs to provide gratuities for services rendered, we understand that tipping is a customary practice and do not discourage the practice in programs where tipping is permitted.
Our organization does not participate in tip pooling. Any gratuity an eligible staff member receives from a program participant is theirs to keep. Staff may choose to give all or a portion of the tip to other staff who also participated in the program. Tips received at the time of the program are the property of the staff. Cash-tips received by the administration office will be forwarded to the appropriate staff. We do not accept gratuities made by check or credit card.
Gratuities are considered taxable wages. Staff are responsible for reporting gratuities on their federal and state income taxes.
Staff who working in the following fee-based programs are eligible and permitted to accept cash only- gratuities:
(List of programs)
If you receive a gratuity while working in a program mentioned above, it is your responsibility to find out the intent of the tipper: if the tip is meant to be solely for you or if it is to be shared with some or all other attending staff members. Accepting a gratuity, but not following the wishes of the gratuity-giver may lead to immediate disciplinary action, up to, and including, termination.
Staff who working in the following donation-based, grant and/or government funded programs are not eligible nor permitted to accept gratuities:
(List of programs)"