I am currently receiving the error “Numbers above 0 are reserved for automatic assignment” when trying to add a new RMA Receipt for an existing RMA using Postman. (sending as JSON).
POST https://svr.sme.com/myinstance/api/v1/Erp.BO.RMAProcSvc/RMARcpts
Body
{“Company”: “MYCOMPANY”,
“RMANum”: 19,
“RMALine”: 4,
“RMAReceipt”: 0,
“WareHouseCode”: “RUK”,
“BinNum”: “01”,
“ReceivedQty”: “1”,
“ReceivedQtyUOM”: “EA”,
“ThisRcptQty”: “1”
}
This error is based on company config
Are you sure the RMANum is correct? It seems to be trying to create an RMAHead record and failing, although it shouldn’t as far as I know. I’ll do some quick testing.
Yes, RMANum definitely correct (its a new system, hence the low number. I’ll check out the company config now - Thanks 
Starting order and starting RMA were both 0, changed that to 1 and still the same.
I just tried it and it works fine with the parameters you are sending, I think the problem is the company the postman session is using does not have an RMA with number 19.
By default the company used in REST is the last one the erp user logged into in the regular client. If you want to specify the company/plant you need to send custom header CallSettings in the request.
Brilliant, with the CallSettings header the record is adding now 
, though the RMA Qty is 9 and it’s let me add 5 receipts with Qty 13 but the “This Receipt” Qty on all of them is 0.
Unfortunately I’m not familiar with RMA to know if what you are seeing is acceptable or not, I would try to replicate through the regular client after enabling tracing to see if there is an additional call somewhere that would throw an error, and this additional call is bypassed when using custom method UpdateExt which is what OData uses for updates.
I remember seeing there is a PreUpdate being called before update, maybe this validates the quantities before actually calling Update.
Could you please help me with creating a new RMA head with rest-api? I’ve exhausted all my resources
What are you struggling with, are you using Postman ?