JLA Accountants: a practice's site, rebuilt off WordPress

Mobile LCP, home page (WordPress: 12.4 s): 1.7 sMobile LCP, home page (WordPress: 12.4 s)
Home page weight (WordPress: 27 MB): 339 KBHome page weight (WordPress: 27 MB)
Free calculators, no sign-up: 157Free calculators, no sign-up

The brief

JLA Accountants is an accountancy practice in Barnet, North London. Its website, jla.accountants, ran on WordPress. Measured on a phone, the home page took over 12 seconds to show its main content and moved about as it loaded. It weighed around 27 MB, most of it two videos that downloaded as the page opened. Some of the copy was out of date, and the legal pages still had template brackets in them.

The brief was a new site on modern, maintainable code. It had to keep every address that already ranked or was linked to, and the practice's email had to keep working through the switch. It went live on 9 October 2026.

The design

The first design was bold and product-led: heavy sans-serif type, mint on navy, rounded cards and pill buttons. The practice said it felt too much like a software company, and asked for something cleaner and more professional. Two days later, on 23 October, the restyled site went live: a serif for headings, navy with cream and a little brass, square corners and hairline rules, and photographs in place of product mock-ups.

The navy "What brings you to us?" band on the home page, with four numbered cream cards overlapping its lower edge: reduce your tax bill, protect your assets, buy a business, build long-term wealth

A serif is the usual way to lose speed, so we treated fonts as the budget. The variable serif file was 273 KB and cost 8 points of mobile Lighthouse score on its own. We replaced it with static files of 47 KB, and the italic only loads where a page uses it.

157 free calculators

The largest part of the build is a set of free tax and pay calculators: 157 of them, from take-home pay and company car tax to inheritance tax and selling a business. There's no sign-up. The hub has a search that takes people's own words and forgives spelling, so "company car" finds 16 of them.

Each calculator answers as you type, in a plain sentence first, then the figures. It shows how the answer was worked out and which tax year's rates it used, and says whether it's exact or an estimate. You can copy the result, download it as CSV or print it.

The take-home pay calculator's answer for a £45,000 salary: "You'd take home £34,120 a year, about £2,843 a month", labelled as our best estimate, with tiles for the month, week, income tax, National Insurance and how much of the next £100 you keep, and the working beneath

The sums run on the server, not in the browser, so the same engine can serve the practice's other systems later. Nothing anyone types is stored or logged. The calculators have 2,745 automated tests. The hub also lists the calculators on Exit Better, JLA's sister site for selling or passing on a business, which open there.

Service pages

Each of the practice's nine core services has its own page, alongside the four pages for what brings people in. They cover who each service suits, the options and their trade-offs, and common questions. The figures, rates and dates were checked against official sources (GOV.UK, HMRC's manuals and the legislation), with the sources kept alongside the code.

The inheritance tax planning page: "The main ways to reduce inheritance tax", with lifetime gifts and trusts each set out as who it suits, how it works and what to watch out for

On a phone

The site was built for phones as much as desks. The menu folds into one button, and the calculators' answers stack into a single column.

Three phone screens: the home page with the serif headline, the services page on navy, and the take-home pay calculator's answer of £34,120 a year

Moving it without losing anything

Every old address still works. The old site's sitemap listed 19 pages. Fifteen are served at the same address. The other four were thin or out-of-date pages, and each now sends one permanent (301) redirect to the page that replaced it. The old sitemap addresses redirect to the new sitemap.
Email kept running. We moved the domain's DNS to a Cloudflare account in the practice's name, copying every record and checking the mail records before and after. The website switch came after that.
The practice owns the accounts. The domain's DNS and the analytics property are in the practice's own accounts.
No tracking before consent. Google Analytics loads only after a visitor accepts it, and the privacy policy was rewritten to say so.

The stack

Next.js, React and TypeScript, styled with Tailwind CSS. Every page is built ahead of time as static HTML, so nothing above the fold waits on JavaScript. Each change runs through a typecheck, lint, a build, SEO checks on every page and a sweep of the old addresses, and the site deploys automatically when those pass. An accessibility check holds every page type at a Lighthouse score of 100.

The numbers

Lighthouse on mobile, three runs each against the live home page and the old WordPress site (still answering on its old host), on 29 October 2026:

Largest contentful paint 1.4 to 1.7 s, against 10.0 to 14.5 s on WordPress.
339 KB for the whole page, against 19 to 32 MB.
Performance 100 on every run, against 33 to 42. Accessibility 100, against 85.
No layout shift (0), against 1.2 to 1.4, where content jumped as the page loaded.

These are lab runs from our own machine, not field data from real visitors.

Why it's on this site

A practice's website is its front door, and this one was slow and heavy. We measured it, rebuilt it on code the practice owns, moved it without breaking a link or an inbox, and gave it something useful to offer visitors. We also build Fortium, the platform the practice runs on. If your website or system is holding you back, tell us what you're working around.