Private endpoints and VPC peering transfer charges
Parent: Atlas Cluster Topology and Tier Economics · Published reference · snapshot 2026-10-20 · skill ranked-5130ee0b
↓ Facts as markdownall context files
Source-anchored research for Private endpoints and VPC peering transfer charges. Run status: COMPLETED.
These notes link each claim to its source. Some citations identify archived research reports that are no longer hosted on this site. A published reference means the content is available; it does not certify independent review or accuracy.Read the editorial policy and follow the sources before relying on a claim.
Structure and components
- AWS's April 7, 2022 announcement said same-Region inter-AZ data-transfer charges associated with accessing services through a PrivateLink interface endpoint became free on April 1, 2022, while per-GB interface-endpoint data-processing charges remained. AWS's current pricing page still lists endpoint-hour and per-GB processing charges, so a waived transfer component does not make PrivateLink free. (high confidence) (verified as of 2026-10-20) [source]
How it works
- AWS's April 2, 2026 NLB guide says cross-AZ traffic from an NLB to its targets incurs $0.01/GB in each direction at both ends. If both the client-to-NLB and NLB-to-target hops cross AZs, the guide's example reaches $0.04/GB in each direction. It says the same NLB path charges can apply when clients reach an internal NLB through VPC peering. (high confidence) (verified as of 2026-04-02) [source]
Measurements and reference values
- For Atlas dedicated clusters, Online Archive, and Data Federation using AWS PrivateLink, MongoDB bills a regional endpoint hourly and Private Endpoint Capacity Units hourly. Atlas capacity units reflect the largest hourly usage among new flows, active flows, and processed bytes; the processed-byte dimension is 1 GB per hour per unit. AWS separately bills each customer interface endpoint per provisioned Availability Zone-hour and per GB processed. Cross-region PrivateLink also incurs AWS inter-region data-transfer charges. (high confidence) (verified as of 2026-10-14) [source]
- MongoDB's April 18, 2025 billing notice said AWS would begin billing previously under-metered cross-AZ traffic between the Atlas PrivateLink service's Network Load Balancer and its targets from May 1, 2025. MongoDB said it would cover the increment through May 15 and estimated an average 1.0% monthly Atlas-bill increase after that, based on February 2025 usage; actual impact varies with traffic. (low confidence) (verified as of 2025-04-18) [source]
Comparisons and alternatives
- Atlas's AWS data-transfer table lists same-Region transfer at $0.00-$0.01/GB and says Atlas does not charge incoming data transfers to an Atlas cluster. Atlas separately lists private-endpoint service charges, so compare Atlas transfer items, Atlas PrivateLink items, and AWS endpoint or network items rather than assuming private routing removes all transfer costs. (medium confidence) (verified as of 2026-10-14) [source]
- beSharp's January 14, 2026 Atlas worked example compared a public path through a NAT Gateway with VPC peering. Under its stated assumptions, the public path incurred NAT hourly, NAT processing, and internet-egress costs, while peering was free same-AZ and $0.01/GB each way cross-AZ; the model found peering cheaper at every traffic volume. It notes that AZ names do not align across AWS accounts, so its result is a model-specific estimate rather than a universal bill comparison. (medium confidence) (verified as of 2026-01-14) [source]
Facts and statements
- Creating an AWS VPC peering connection has no connection fee. Traffic that remains within one Availability Zone is free even across accounts; traffic crossing Availability Zones or Regions is chargeable. AWS's current VPC pricing lists same-Region cross-AZ peering at $0.01/GB in each direction. AWS says intra-Region VPC peering usage moved to VpcPeering-In-Bytes and VpcPeering-Out-Bytes billing usage types starting in April 2025. (high confidence) (verified as of 2026-10-20) [source]
- Atlas's AWS Data Transfer Costs page lists same-Region data transfer at $0.00–$0.01/GB, different-Region transfer at $0.02–$0.15/GB, and Internet egress at $0.09–$0.16/GB. It says incoming transfers to an Atlas cluster are not charged and Free and Flex tiers are not charged for outgoing data. The page describes transfers between an Atlas node and another node but does not explicitly identify whether its same-Region row applies to application traffic carried over customer VPC peering. (low confidence) (verified as of 2026-10-14) [source]
- For AWS PrivateLink to Atlas, MongoDB bills a regional Atlas private-endpoint hourly charge and hourly Private Endpoint Capacity Units (CUs). A CU is set by the highest usage of new flows, active flows, or processed bytes during that hour. AWS separately bills each provisioned interface endpoint per hour in each Availability Zone and charges per GB processed. AWS's current tier schedule is $0.01/GB for the first 1 PB per Region, $0.006/GB for the next 4 PB, and $0.004/GB above 5 PB. (high confidence) (verified as of 2026-10-20) [source]
- AWS charges nothing to create a VPC peering connection, and data that stays within one Availability Zone is free even across accounts. AWS lists same-Region VPC-peering traffic that crosses Availability Zones at $0.01/GB in both the In and Out directions; cross-Region peering also incurs applicable inter-Region data-transfer charges. (high confidence) (verified as of 2026-10-20) [source]
Children
- No children recorded.