Although your company may be small, if there's a group of workers who travel more or less habitually for work, a clear corporate expenses policy is something your firm should have. Producing a corporate document containing all those rules that you and your team more or less know will help you to make them official and create a solid basis to tackle any possible incidents.
Creating an expenses policy doesn't have to be a hugely complex task. You're not starting from scratch. It's not the first time your team has reported their expenses and you know what most of them are. You just have to take all this knowledge and put it down in black and white, with all that this involves: exploring the range of possible situations, establishing exact figures for each point, setting clear limits, etc.
One golden rule is to be clear and concise. A good expenses policy must be easy to understand and remember. It's often useful to divide it into sections. Hotels, meals, travel... This will make it easier for you to construct possible scenarios and regulate them, and it'll be much easier
It's also useful to add a specific section for non-refundable expenses. You can use your experience. What non-refundable elements do you normally get together with your team's expense claims? Meals with companions, alcohol, expenses occurring outside the working day? You know what they are, better than anyone.
And it's also advisable to inform the team regarding what measures will be taken to ensure compliance of the expenses policy. It's not a bad idea to remind them that the expense claims will be checked carefully, one by one, by someone in charge; and that they might be rejected if they're not according to the rules described.
Another important point to take into account is that, if you decide to make a corporate expenses policy official, then you have to monitor it. The expense reports must be duly and thoroughly checked. If not, you'll probably find that the rules won't be followed so closely.
Lastly, the company's expenses policy doesn't have to be a definitive document. Test and iterate, but do so in an organised way. If not, you might confuse your staff.
Would you recommend anything else for setting up a corporate expenses policy properly?