Car Wash Monthly Package Subscriber and Wash Balance Tracker

Car Wash Package Subscriber Tracker is an offline app (one HTML file in a zip) for a car wash that sells packages such as eight washes in thirty days. You list your packages once and add each subscriber with the plate, the start date and what they paid. Every wash for a subscriber is a line in the wash log, and the app counts down what is left.

The problem it removes: Subscribers claim washes that were already used, come back after the package expired, or never renew because nobody calls them. The counts live on a card in the cashier's drawer. This app counts washes used against the package, refuses a wash that is not allowed, and lists who is about to expire or has run out.

What is inside:

• A package list with the number of washes, the price and the number of days it lasts
• Subscribers with plate, start date, amount paid, expiry date, washes used, washes left and a status
• A wash log that refuses a wash when none are left, before the start date or after the expiry date
• A balance owed per subscriber and a list of packages not yet paid in full
• One button to create renewals for expired or used up packages, and a WhatsApp reminder list for expiring ones
• A printed subscriber card and a printed expiry list
• Example data you can load in one click, a Start here guide and an Honest limits panel
• JSON backup and restore, CSV export, and CSV import with a check of every row before anything is added

Who it is for: owners of car washes and detailing shops who sell prepaid wash packages to regular customers and want an accurate count without a card in a drawer.

What it is NOT: It does not sell a package online, take a card payment or recognise a plate by camera. It does not carry unused washes into a new period unless you add them to the new package. The expiry is the start date plus the number of days you set for the package. It is not legal, tax or accounting advice, it is not connected to any government system, bank or messaging service, and it does not file or send anything by itself. UAE e-invoicing is not part of it.

Your data stays on this device in your browser. Back it up with Export; clearing browser data loses it otherwise.

Verified by us: scripted tests in Chromium (127 checks through the real screens: adding, editing and deleting records in every table, required-field messages, backup then clear then restore, CSV export then import, keyboard order, print layouts rendered to PDF, no horizontal scrolling at 375 and 1280 pixels, no network requests) and an independent recalculation by a separately written Python evaluator of 726 calculated values (25 randomised rows plus the example data) with 0 mismatches. Safari engine (WebKit): smoke test passed; Firefox: could not be launched. Not tested: Firefox beyond what is stated here, and no real printer was used (print layouts were checked as PDF).