This can depend on the payment method that you use. Most payments should be processed immediately, although some payment methods such as PayPal or bank transfer could take 2-3 business days.
To check if your payment has been received, go to your Wallet (https://mynxu.nexford.org/wallet) and check your Account History.
If you cannot see your payment reflected in your Account History and/or have questions about the status of an existing transaction, contact billings@nexford.org