How do I pay people that aren't signed up with the Chamber if Commerce?
The most important thing for your records is to have proof of payment for expenses you have incurred. So if you hire someone, who is not a business owner, handle it the way below.
(receiving) A receipt
A receipt is similar to an invoice, but different: it is a document signed by the person you are working with (who is not registered at the Chamber of Commerce). He/she certifies that you have paid and that you have received the goods or services.
A receipt should make clear what your cooperation partner has done for you and for what amount. The receipt must be addressed to you as the principal (and payer), it must show the date the services were rendered, and it must conclude with your name and signature.
You can forward the receipt (with Plus) or process it yourself in the accounts. This will lower your profits and thus reduce the tax to be paid. So even if the company asks for an invoice, never start invoicing as an individual. Make a receipt, which is a valid document for your client's business records.
Can your collaboration partner create a receipt in a free version of The Bookie Webapp?
Yes. By creating a free account of The Bookie Webapp, someone can create an invoice in The Bookie Webapp and thus meet the requirements of a receipt. (In addition, this is also useful for your collaboration partner so that all income from freelance jobs is listed for income tax purposes)
Then either a digital the invoice can be emailed with signature or the invoice can be printed and then scanned to you with signature.