Quick definition
Net metering credits build up and get drawn down all year, since solar production and household usage rarely match exactly month to month. Summer months often produce more credit than a home uses; winter months often draw down more than the home produces. The true-up date is when the utility looks back over the full year and settles the running balance, applying whatever rules the specific program sets for any leftover surplus or shortfall.
It's the once-a-year reconciliation point, distinct from the ongoing month-to-month credits that accumulate throughout the year.
At a glance: true-up dates vary by utility and are sometimes tied to a customer's specific interconnection anniversary rather than a single fixed calendar date shared by every customer.
Why it matters
What happens at true-up can meaningfully affect actual solar savings, especially for a system sized to closely match a home's annual usage. If a homeowner ends the year with more credit than they used, largely thanks to strong summer production, the true-up rules determine what happens to that surplus: some programs pay it out at a set rate, some let it roll into the next year, and some simply forfeit it. These are genuinely different outcomes for the homeowner's bottom line, not just a technical formality.
This is exactly why understanding your specific program's true-up policy matters more than just knowing net metering exists in general. A program that lets credit roll forward indefinitely is far more forgiving of a system that's slightly oversized for winter usage than a program that forfeits unused credit at the end of each true-up cycle.
The true-up mechanism is also part of why system sizing conversations sometimes intentionally avoid maximizing production. A system sized to generate significantly more credit than a home could realistically use, especially under a program with an unfavorable true-up payout rate, can waste some of that extra production's value rather than translating it into real savings. DSIRE's database of state incentives and policies lists the net metering and true-up rules that apply in each state.
Where you'll see this
The annual true-up payment estimator projects what your specific accumulated balance is likely to look like at your program's true-up date.
For a community solar subscription with its own annual reconciliation, the community solar annual true up estimator runs the equivalent calculation for that structure.
This term comes up in net metering program documentation, on the specific bill issued at the true-up date each year, and any system sizing conversation weighing how much surplus production is actually worth generating. California's solar consumer guide explains how the annual true-up settles a net metering customer's credits and charges.
Related terms
Frequently asked
This depends entirely on your specific program. Some utilities pay out surplus credit at a set rate, often lower than the retail rate, some let it roll forward, and some forfeit unused credit entirely. Checking your specific program's true-up policy matters, since these outcomes are meaningfully different for a homeowner's actual savings.
No. The true-up date is typically set by the utility and can be tied to a customer's specific interconnection anniversary date or a fixed calendar date the utility applies to all net metering customers, depending on the program's specific rules.
If your usage exceeded your accumulated credits over the true-up period, you'd typically owe the utility for that net shortfall, similar to how a standard monthly bill works but settled on an annual cycle instead.
A system sized very close to annual usage is more sensitive to how surplus credit gets treated at true-up, since even a modest seasonal imbalance, more production in summer than usage in winter for example, could result in unused credit that's paid out at a lower rate or forfeited depending on the program.