Move Azure Function Apps to another Service Plan

It’s not possible to move a Azure Function Apps to another Service Plan in the portal.
You need to do this in Powershell in some simple steps:

Get the Ressource ID from your new Service Plan :

$afa_plan = Get-AzureRmAppServicePlan -ResourceGroupName $RG -Name $App_Name 

Then just use the Set-AzureRMResource cmdlet to apply the updated properties :

$afa_properties = @{'serverFarmId'=$afa_plan.Id}
Set-AzureRmResource -Kind functionapp -ResourceGroupName $RG -ResourceName $AFA_name -Properties $afa_properties -ResourceType "Microsoft.Web/sites"

That’s all !