The payasyougo billing method allows you to pay for the resources that you use. If you want to create or delete NAT gateways on demand, you can purchase payasyougo NAT gateways instead of subscription NAT gateways. This topic describes the billing rules of payasyougo NAT gateways.
Description
Overview
The payasyougo billing method allows you to pay for the resources that you use.
 You are charged for payasyougo NAT gateways in each billing cycle. Bills are generated and fees are deducted from your account after each billing cycle.
 You can delete payasyougo NAT gateways anytime. After you delete a NAT gateway, the NAT gateway is no longer billed. For more information, see Delete a NAT gateway.
 High and guaranteed performance to withstand traffic spikes (payasyougo NAT gateways)
Specification Maximum number of connections Maximum number of new connections Throughput Default 2,000,000 100,000 5 Gbps Maximum quota that you can apply for by submitting a ticket 10,000,000 1,000,000 100 Gbps  Internet NAT gateways and VPC NAT gateways support the payasyougo billing method.
PaybyCU
Total amount that you must pay for a paybyCU NAT gateway = Instance fee + Capacity unit (CU) fee. You are charged on an hourly basis. Bills are generated every hour. If you use a NAT gateway for less than 1 hour, the usage duration is rounded up to 1 hour.
 Instance fee = Instance unit price (USD/hour) × Usage duration (hours)
The usage duration is the period from the time when the NAT gateway is purchased to the time when the NAT gateway is deleted.

CU fee per hour = CU unit price (USD/CU) × Number of CUs
Number of CUs consumed per hour by a NAT gateway = Max(Number of CUs based on new connections per hour, Number of CUs based on concurrent connections per hour, Number of CUs based on data transfer per hour)
New connections, concurrent connections, and data transfer are three metrics to CUs. The following table describes how the number of CUs per hour for each metric is calculated.Metric Unit CU coefficient Calculate the number of CUs per hour Connections per second (CPS) Second 1,000 The system collects all CPS values within a billing cycle and then divides the highest CPS value by the CU coefficient to calculate the number of CUs. Concurrent connections (CONNS) Minute 10,000 The system collects all CONNS values within a billing cycle and then divides the highest CONNS value by the CU coefficient to calculate the number of CUs. Data transfer (bytes) Hour 1 GB The system collects the total amount of data transfer including the inbound and outbound traffic within a billing cycle. Then, the system divides the total amount by the CU coefficient to calculate the number of CUs. Note The amount of outbound and inbound network traffic collected by the system equals the amount of network traffic to be processed by a NAT gateway.The following table describes the instance unit prices and CU unit prices for paybyCU NAT gateways.Note If the prices in the following table are different from those on the buy page, the prices on the buy page shall prevail.Region Instance unit price (USD/hour) CU unit price (USD/hour) China (Hangzhou) 0.034 0.034 China (Shanghai) China (Chengdu) China (Shenzhen) China (Heyuan) China (Qingdao) China (Beijing) China (Zhangjiakou) China (Hohhot) China (Ulanqab) China (Hong Kong) 0.043 0.043 UK (London) Japan (Tokyo) Singapore (Singapore) Australia (Sydney) Germany (Frankfurt) US (Silicon Valley) US (Virginia) Malaysia (Kuala Lumpur) Indonesia (Jakarta) India (Mumbai) UAE (Dubai) Example of CU fee calculation
You created three enhanced NAT gateways that use the paybyCU metering method in the UK (London) region at 08:10:00 (UTC+8) on July 8, 2020. Then, you released the NAT gateways at 08:50:00 (UTC+8) on July 8, 2020. The following table describes the highest CPS value, the highest CONNS value, and the total amount of data transfer of the NAT gateways within the time period from 08:10:00 (UTC+8) to 08:50:00 (UTC+8).Metric Data collected from NAT Gateway 1 Data collected from NAT Gateway 2 Data collected from NAT Gateway 3 Highest CPS value (connections/second) 1100 32 0 Highest CONNS value (connections/minute) 20000 8 0 Total amount of data transfer (GB/hour) 3.5 0.0056 0 The numbers of CUs are calculated by using the following formulas:
The CU fee is calculated by using the following formula:Number of CUs based on CPS = Highest CPS value/CU coefficient Number of CUs based on CONNS = Highest CONNS value/CU coefficient Number of CUs based on data transfer = Total amount of data transfer/CU coefficient
CU fee = Max(Number of CUs based on new connections per hour, Number of CUs based on concurrent connections per hour, Number of CUs based on the amount of data transferred per hour) × CU unit price
Number of CUs Data collected from NAT Gateway 1 Data collected from NAT Gateway 2 Data collected from NAT Gateway 3 Number of CUs based on CPS 1100÷1000=1.1 32÷1000=0.032 0 Number of CUs based on CONNS 20000÷10000=2 8÷10000=0.0008 0 Number of CUs based on data transfer 3.5÷1=3.5 0.0056÷1=0.0056 0 CU fee (USD) 3.5×0.043=0.1505 0.032×0.043=0.001376 0
Paybyspecification (applicable only to some of the existing Internet NAT gateways)
Newly purchased payasyougo NAT gateways only support the paybyCU metering method.
Existing payasyougo NAT gateways support the paybyspecification metering method. These NAT gateways have three sizes: small, medium, and large. The unit price of a NAT gateway varies based on the size of the NAT gateway. The following table describes the unit price of each size.
Region  Small (unit price)  Medium (unit price)  Large (unit price)  

(USD/hour)  (USD/day)  (USD/hour)  (USD/day)  (USD/hour)  (USD/day)  
China (Qingdao)  0.076  1.829  0.146  3.505  0.287  6.888 
China (Beijing)  
China (Zhangjiakou)  
China (Hohhot)  
China (Ulanqab)  
China (Hangzhou)  
China (Shanghai)  
China (Shenzhen)  
China (Heyuan)  
China (Chengdu)  
US (Virginia)  0.102  2.448  0.190  4.572  0.375  8.991 
China (Hong Kong)  
Japan (Tokyo)  0.122  2.926  0.233  5.608  0.457  10.972 
Singapore (Singapore)  0.114  2.743  0.222  5.334  0.433  10.363 
Indonesia (Jakarta)  
Australia (Sydney)  0.152  3.657  0.293  5.334  0.573  13.716 
Malaysia (Kuala Lumpur)  0.109  2.606  0.211  5.068  0.410  9.845 
India (Mumbai)  
US (Silicon Valley)  0.108  2.591  0.210  5.029  0.401  9.601 
UAE (Dubai)  0.229  5.486  0.439  10.515  0.860  20.64 
Germany (Frankfurt)  0.137  3.292  0.262  6.309  0.515  12.344 
UK (London)  0.132  3.168  0.253  6.072  0.494  11.856 
Overdue payments
 The NAT gateway can still serve your workloads within 15 days after the payment becomes overdue.
 If the outstanding amount is not paid 15 days after the payment becomes overdue, the NAT gateway is suspended. You cannot manage a suspended NAT gateway.
 If the outstanding amount is not paid 15 days after the NAT gateway is suspended, the NAT gateway is automatically deleted. An email notification is sent to you one day before the NAT gateway is deleted. After the NAT gateway is deleted, the configurations and data of the NAT gateway are deleted and cannot be recovered.
Top up your account balance
 If you top up your account balance within 15 days after the payment becomes overdue, your service is not interrupted.
 If you top up your account balance within 30 days after the payment becomes overdue, the system automatically pays the amount due. After the system pays the outstanding amount, the NAT gateway immediately starts to provide services.