Ask the internet what tools a small business needs and you get affiliate lists forty products long. Ask a business that actually runs lean and the answer is a handful of categories, each doing one job well. Here is the functional map — what each category is for and what to look for — without pretending one vendor is the only answer.

Money first

  • Bookkeeping: a tool that connects to your bank, categorises transactions and produces the figures your tax return needs. If you are approaching MTD for Income Tax territory, choose one on HMRC’s recognised list.
  • Business banking: a separate account, even as a sole trader. Mixing money costs hours at every year end and makes the 13-week forecast impossible.
  • Invoicing: often inside the bookkeeping tool — what matters is sequential numbering, payment terms stated clearly, and a payment link.

Presence and work

  • Website: one credible page beats a broken elaborate site — what you do, who it is for, how to buy or contact.
  • Email: an address on your own domain reads as a business; a free webmail address reads as a hobby.
  • Documents and storage: a suite you actually use daily, with automatic backup — losing the laptop should cost the laptop, not the records.
  • Contracts: even sole traders need terms — scope, price, payment terms, IP — sent before work begins. Templates from trade bodies and the Federation of Small Businesses cover most cases.

The invisible essentials

Two categories get forgotten until they hurt: a password manager — the business’s keys, treated seriously — and insurance appropriate to the work (professional indemnity for advice, public liability for premises and customers). Neither is exciting; both are cheaper than the events they insure against.

For the MTD-relevant categories, HMRC’s recognised software lists on gov.uk are the neutral starting point.

The audit worth doing yearly

Tool sprawl is silent. A free trial becomes a subscription, a second tool overlaps the first, and a year later the monthly bill is a surprise. Once a year, list every subscription the business pays and ask of each: what breaks if this disappears tomorrow? If the honest answer is “nothing”, cancel it before the next renewal. The savings are rarely dramatic — but the habit of asking is the difference between a stack and a pile.

One more discipline: keep the business’s accounts in the business’s name, on a card or direct debit you can see in one place — not scattered across a personal PayPal. When the bookkeeping tool pulls every subscription into one feed, the yearly audit takes ten minutes instead of a forensic weekend.

How much should tooling cost a one-person business?

There is no rule — but a sensible default is that the total monthly software bill should be small relative to one billable hour. If the stack costs more than an hour of your rate per week, audit it.

The hidden category worth one more line: people. Not software, but the accountant who answers email, the trade association helpline, the peer who has done this before — most one-person businesses underinvest in advice because it does not look like a tool. Budget for an hour of professional advice a quarter; it will outperform most of the subscriptions on this list.

When should I upgrade from free tiers?

When a specific limitation costs you time or money — a missing bank feed, a capped invoice count, no accountant access. Upgrade for the feature, not the feeling.

Start with the money categories and add the rest only as the friction demands. The best stack for a one-person business is the smallest one you never think about.

Do I need a CRM?

Most one-person businesses need a contacts list and a habit of following up — a spreadsheet does that until the pipeline genuinely outgrows it. Buy the CRM when losing track of leads is demonstrably costing sales.