AKV payout

I'd like to jump in with this question.
I'm also wondering how this should be done.

What I can tell you for sure is that there is a good chance you will be paid more than 500 euros this way, which means you will probably owe 5% social security contributions on the amount paid out.
I would solve this by doing the calculation of dividing the amount owed (e.g. 90 euro) by 1.05. This is what your fellow musicians will receive (100%+5%). They will therefore receive 85.71 euro and you will keep 4.29 euro to ultimately pay that 5% contribution.

That way, you don't have to pay that tax out of your own pocket out of goodwill towards the musicians.
You split decent fees with a rehearsal.

Does anyone have an answer to this question? I'm facing the same issue...

Answer from Dexxter:
"We are not yet very familiar with this reimbursement, so we cannot guarantee whether you can/must enter these expenses in Dexxter. For that information, it is best to contact the organisation Working in the Arts.

If you are sure that you are allowed to invoice and pay your fellow musicians yourself, you can enter the payment to the musicians in your accounts via Reports > Income & expenses and select "manual input" in the top right-hand corner.
There, you can add a line under 'other services', fill in the amount and give it a description.

You will still need to keep documentation of this so that you can account for it. In my opinion, the summary from the Working in the Arts portal is sufficient evidence!
I don't know how to enter the 5% solidarity contribution.

I checked with Working in the Arts and received this answer:
"It is not possible to download a certificate/attestation for your accountant via the "Workinginthearts" website. This functionality is not provided. However, you can view your declaration history via the website.

You can take a screenshot of this and print it. If you prefer a more official document, you can also question the various artists involved to send you a receipt."