Hi Fanda,
Pretty much normal rules apply. Invoices and paper trail is a must. All landing fees, fuel upflifts (I presume you take the A/C dry?) can simply be claimed as an expense, and then get the group administrator to raise an invoice for the tacho time at the agreed rate to your company.
The one big disadvantage is the weather. More than once I've sat in a meeting that I've flown to, more worried about the front that's moving in, than the contents of the meeting. Be careful not to put pressure on yourself to fly. The meeting may be mega important, but the conditions to fly not favourable or perhaps marginal. You must very clearly take your business hat off, and you pilot hat on. Be careful.