When a provider asks to switch an incall to outcall and says she will make the arrangements, what's the protocol for picking up the hotel cost?

If you've booked and paid for an incall and she needs to switch to an outcall due to something on her end, then the cost is on her, though she may just choose to cancel instead.  

Incall = her place or she reserves and pays for the room. It's hers to use as she needs for as long as the room is booked (presumably till the next AM)

Exactly. If she's getting the room then that's an incall. Nothing wrong with jacking up the rate to cover that cost, if it's up front. If she's getting the room and then forwarding the bill to the OP, and if they had already confirmed, that's an upsell. We all covered this recently.

I agree with JohnL and fearghas

Once, a few hours before our appointment, my ATF told me that her incall apartment was suddenly unavailable, and asked me if I wanted to get a hotel room for us. Because I was her only appointment for the day, she didn't want to get the room herself, and offered to reschedule. But I was really looking forward to seeing her that night, so I got a reasonably priced room in a middle class suburb near my home. She thought the place looked a little shady on the outside, but admitted the room was fine. This only happened once, and all our other appointments have been at her incall apartment or her incall hotel room.

If she is "making the arrangements" then it is still technically an "incall" You are going to HER hotel room, and unless she is trying to upsell you for the cost of the room, the room should be her responsibility.

you have heard from the others and I agree, if she makes the arrangements then it's still an incall and the cost is on her.

I haven't had a provider specifically phrase things to me that same way. However, I have requested a provider to offer me an incall at a more convenient location than their normal incall locale. Since my location preference was more costly, she asked me to split the difference. I just added the (full) cost of the room to her envelope, since she went to the extra effort of making arrangements and traveling a few minutes further for me.  

It really just depends on the circumstances but if I did it last minute, I would probably pay.   If it was outrageous and the only way I could honor the appt was to make the switch, I might just share that with you and discuss the realities ina down to earth manner.

Thanks to all for the helpful responses.

I had one girl ask if I would let her stay and use the room for the rest of the night... I said no.

but he would demand otherwise and pick up the room tab over her objections. lol

If you get the hotel room, it is yours. You don't let her then go use it for others because it will slap you in the face potentially. It is also an outcall as she'd be coming to your "place".

... "hotel incalls" which means I book the room and charge  extra to cover the cost of the room. That's all upfront and mentioned on my site with donation costs. If something changes and the room is extra or that particular hotel is booked, the costs and arrangements are still on me.