When an individual uses personal funds (or personal credit) to pay for a campaign expense, that payment is generally an in-kind contribution from that individual. For example, an in-kind contribution results if a campaign staff member pays for postage, office supplies or campaign materials with personal funds. This rule also applies to payments made by volunteers and by the candidate.
Travel expenses later reimbursed by the committee are treated differently
Although such advances are considered in-kind contributions until reimbursed, special reporting rules apply when individuals pay for campaign expenses and later receive reimbursement from the committee.
The official staff of members of Congress cannot contribute to their employing member’s campaign. As such, it is important for those individuals to avoid advancing any funds to the campaign (for example, buying stamps for a campaign mailing).