How should a startup calculate a reasonable per diem rate for sales associates? Is is typical to expense every single purchase while traveling for work?
Not saying that is the end all of resources, but it is a place to start. Per diems are nice, as a consultant I used to make good money on the per diems, because usually I could do better on my expenses when I traveled. It does save a lot of money in terms of reimbursement management from the company side so that is a trade off, but if you are pinching every penny, I'd do reimbursements and put people on a reasonable budget when they travel, e.g. explain that no, the $100/steak dinner won't be covered as that is excessive. I can't remember the specific wording on this, but you can check with your payroll provider or attorney on it, but you can limit people from excess when doing reimbursements. And you may want to check with the attorney or payroll/tax person as well, because it used to be (and I don't know if it still is) you could set a per diem and/or do reimbursement. What that meant was that you can say you reimburse all expenses up to the maximum of the per diem rate, but I am not sure if this is still ok to do, but I worked for a few companies with this rule and it was fair IMO. At the same time, you should obviously exclude client events, e.g. your sales person takes the client to dinner, that's obviously excluded from the per diem or limits.
The one thing to be really careful of, don't tell people after 5pm they are on their own time so the company doesn't cover them, that can get you into trouble if they file a complaint (typically with wage and labor board in most states). If someone is traveling on business for your company, even if that means over a weekend or typical company holiday, they are to be reimbursed for all reasonable expenses, or are eligible for a per diem. When I ran my consulting businesses I just gave a fair but higher per diem and said screw it, just made life way easier. Easier to budget and plan plus in our case we could pass the cost on to the client (so we didn't make it crazy either). When you are doing sales, the costing isn't as clean but a per diem does help budgeting as you are learning the process.