# Lot Sidekick > Lot Sidekick is billing software for small mobile-home-park owners (roughly 10 to 100 lots): flat-priced rent and submetered water billing that replaces a spreadsheet. Owners record rent and water payments — cash, money order, or check — against a real, append-only ledger, and residents get a clear, itemized bill. Lot Sidekick also runs a free public directory of mobile home parks, built from official state licensing/registry data and enriched with EPA public water system records, FEMA flood zone maps, HUD Fair Market Rent benchmarks, and county parcel/assessment records where those are available. Every fact on a park page carries its own source and an as-of date — nothing here is estimated or guessed. A park owner can claim their page for free to add a verified phone number, website, or real lot rent. ## The Lot Rent Index - [The Lot Rent Index](https://lotsidekick.com/data/lot-rent): the citable tracker — 12,942 registered mobile home parks in 604 counties across 13 state registries, with lots, reported vacancies, HUD Fair Market Rent by county, EPA water systems and FEMA flood exposure. One page per state at https://lotsidekick.com/data/lot-rent/. Updated quarterly; free to quote with a link. ## Park directory - [Directory index](https://lotsidekick.com/parks): 12,942 registered mobile home parks across 13 states, 987,458 total spaces, organized by state and county - [California](https://lotsidekick.com/parks/california): 4,053 registered mobile home parks, per the state registry as of 2026-08-24 - [Colorado](https://lotsidekick.com/parks/colorado): 625 registered mobile home parks, per the state registry as of 2026-07-23 - [Connecticut](https://lotsidekick.com/parks/connecticut): 181 registered mobile home parks, per the state registry as of 2026-07-27 - [Florida](https://lotsidekick.com/parks/florida): 2,294 registered mobile home parks, per the state registry as of 2026-07-22 - [Illinois](https://lotsidekick.com/parks/illinois): 617 registered mobile home parks, per the state registry as of 2026-07-23 - [Indiana](https://lotsidekick.com/parks/indiana): 1,055 registered mobile home parks, per the state registry as of 2026-07-23 - [Maine](https://lotsidekick.com/parks/maine): 464 registered mobile home parks, per the state registry as of 2026-07-23 - [Michigan](https://lotsidekick.com/parks/michigan): 887 registered mobile home parks, per the state registry as of 2026-07-23 - [New York](https://lotsidekick.com/parks/newyork): 1,167 registered mobile home parks, per the state registry as of 2026-07-22 - [North Dakota](https://lotsidekick.com/parks/north-dakota): 251 registered mobile home parks, per the state registry as of 2026-07-23 - [Oregon](https://lotsidekick.com/parks/oregon): 1,064 registered mobile home parks, per the state registry as of 2026-07-19 - [Rhode Island](https://lotsidekick.com/parks/rhode-island): 46 registered mobile home parks, per the state registry as of 2026-07-23 - [Vermont](https://lotsidekick.com/parks/vermont): 238 registered mobile home parks, per the state registry as of 2026-07-23 - [Claim a park](https://lotsidekick.com/parks/claim): free — for a park owner to add real contact info and rent to their own page ## Free tools - [All tools](https://lotsidekick.com/tools) - [Water submeter calculator](https://lotsidekick.com/tools/water): Two meter reads and your utility's rate in, a tenant's at-cost water bill out. The no-markup math, done right. - [Water billing run (reads → invoices)](https://lotsidekick.com/tools/water-billing): Paste or upload the whole park's submeter reads, set your rates once, and get an itemized bill for every lot — print, PDF, CSV, or copy-ready texts. - [Lot rent increase calculator (2026 caps)](https://lotsidekick.com/tools/rent-increase): The most you can legally raise lot rent this year — Oregon and Washington caps applied to your park size and rent. - [Rent-increase notice generator](https://lotsidekick.com/tools/notice): A clean, printable rent-increase notice with the effective date and notice period filled in. PDF download included. - [Late rent notice generator](https://lotsidekick.com/tools/late-rent-notice): A past-due notice for one lot, with the rent and late fees itemized so the total can be checked. Print it or download the PDF. - [Rent payment plan agreement](https://lotsidekick.com/tools/payment-plan): Back rent, the monthly rent, and a catch-up amount in — how many months it takes to clear and a signable agreement out. - [Utility bill-back notice](https://lotsidekick.com/tools/billback-notice): What trash, water, or sewer really costs per space per month, plus the notice that moves it out of the rent and drops the rent to match. - [Rent receipt generator](https://lotsidekick.com/tools/rent-receipt): A printable receipt for a cash, check, or money-order rent payment — two copies to a sheet, one for the resident and one for your file. - [RUBS calculator (master-meter split)](https://lotsidekick.com/tools/rubs): Split one master-meter water bill across your lots so the pennies add up exactly, with a park share held back. - [Prorated rent calculator](https://lotsidekick.com/tools/prorate): Mid-month move-in? Get the exact partial-month rent, by actual days in the month or a flat 30-day month. - [Park value & profitability estimator](https://lotsidekick.com/tools/park-value): Lots, lot rent, and a cap rate in — annual NOI and what the park is worth out. The math buyers and lenders actually use. ## Company - [Pricing](https://lotsidekick.com/pricing) - [Contact](https://lotsidekick.com/contact) ## Optional - [Terms of service](https://lotsidekick.com/terms) - [Privacy policy](https://lotsidekick.com/privacy)