Best Cash Flow Forecasting Software for UK Accountants in 2026

Cash flow forecasting software takes the bank, sales and purchase data already sitting in a client's ledger and projects the cash position forward, week by week or month by month, so a practice can spot a shortfall before it arrives. For UK accountants the realistic shortlist is short: a dedicated forecasting app such as Float, a reporting suite such as Fathom or Syft, or the forecast built into Xero itself.

TL;DR:

Cash flow forecasting software pulls actuals from Xero or QuickBooks and projects cash forward; it does not replace judgement about what clients will actually pay and when.

Xero's own forecast is bundled with its UK plans and runs 30, 60, 90 or 180 days depending on the plan, from £18 to £70 a month excluding VAT.

Float publishes UK pricing from £99 a month (£79 billed annually) for businesses under £2m revenue, with a 14-day free trial and no card required.

Fathom and Syft are reporting suites first, with forecasting inside; they suit practices that want forecasts and management packs in one place.

The government says late payment costs the UK economy £11 billion a year, which is why the receivables side of a forecast deserves the most scrutiny.

What does cash flow forecasting software actually do?
Why are UK accountants being asked for forecasts now?
Which cash flow forecasting tools fit a UK practice?
How much does cash flow forecasting software cost in the UK?
Is the Xero built-in forecast enough?
How do you roll out forecasting across a client base?
Why does independent evidence matter when choosing cash flow forecasting software?
Realistic expectations: what a forecast can and cannot tell you
Find your next cash flow forecasting tool through The AI Ledger

What does cash flow forecasting software actually do?

At its simplest, a cash flow forecast answers one question: how much cash will this business have in the bank on a given future date? Spreadsheets can answer it, but they go stale the moment a new invoice is raised or a bill is paid. Forecasting software connects to the accounting ledger and keeps the starting point current.

Most tools in this category do four things:

Pull actuals automatically. They read bank balances, open sales invoices, unpaid bills and historical transactions from Xero, QuickBooks or another ledger, so the forecast starts from today's real position.
Project forward. They use due dates on open invoices and bills, plus recurring patterns in past data, to estimate future receipts and payments.
Model scenarios. They let you ask "what if": a new hire, a delayed customer payment, a lost contract or a loan drawdown, and show the effect on the cash line.
Present the result. They produce a chart or report a client can understand without reading a spreadsheet.

The AI element varies. Some tools use pattern recognition to suggest recurring items or categorise transactions, and some, such as Fathom, now draft written commentary. The directory record for Fathom describes an AI Commentary Writer that drafts source-linked report narratives. None of these features removes the need for an accountant to check the assumptions.

Pro Tip: Before comparing tools, decide which horizon your clients need. A 13-week weekly view catches tight weeks around VAT and payroll; a 12-month monthly view answers whether a client can afford a hire. Some tools do one well and the other adequately.

Why are UK accountants being asked for forecasts now?

Two pressures are pushing forecasting up the agenda for UK practices: late payment and tax timing.

On late payment, the government's response to its 2025 consultation states that late payments cost the UK economy £11 billion each year and lead to the closure of 38 UK businesses every day. The same document says business owners affected by late payment waste 86 hours a year chasing invoices. The response, updated on 24 July 2026, sets out measures including a maximum payment term of 60 days with limited exemptions, implemented no earlier than 2027, and mandatory interest at 8% above the Bank of England base rate on late payments.

For an accountant, those numbers explain why a forecast built on invoice due dates is often optimistic. If customers pay late, the forecast must reflect when they actually pay, not when they should.

On tax timing, VAT, PAYE and corporation tax payments are large, predictable outflows that small businesses routinely forget to plan for. HMRC's guidance is that a business must pay its VAT bill by the deadline shown on its VAT return. A forecast that already contains those dates turns a quarterly surprise into a planned payment.

There is also a commercial reason. Forecasting is a natural advisory service: a monthly cash review sits between compliance work and full virtual finance director support, and software makes it repeatable across many clients rather than a bespoke spreadsheet for each.

Which cash flow forecasting tools fit a UK practice?

The tools below are all listed in The AI Ledger directory. Editor scores and pricing come from the directory records and the vendors' own pricing pages, checked in September and October 2026.

Tool	Best for	Editor score	Published pricing	UK fit
Float	Dedicated cash forecasting and scenarios for practices	4.6 out of 5	From £99 a month, or £79 a month billed annually	GBP pricing, Xero and QuickBooks Online sync
Fathom	Management reporting packs with three-way forecasts	4.5 out of 5	Pro from US$450 a month for 25 companies; Portfolio from US$67 a month	GBP billing offered; integrates with Xero, QuickBooks and FreeAgent
Syft Analytics	Client-ready reporting, benchmarking and consolidations	4.4 out of 5	Free Basic tier, then per-entity Plus and Advanced plans	Owned by Xero; deepest Xero alignment
Xero Analytics Plus	Quick short-term forecast for clients already on Xero	4.2 out of 5	Bundled with Xero plans, £18 to £70 a month	Native to Xero UK plans
Datarails	Excel-first FP&A for larger, multi-entity clients	4.5 out of 5	Not published; quoted after a demo	Suits finance teams more than small practices

A few notes on each.

Float is the specialist. The directory verdict calls it one of the most accountant-friendly cash flow tools, strong on visuals and scenarios, with a caution to check multi-currency limits. Float's pricing page lists live sync with Xero and QuickBooks Online, with Sage Intacct and Iplicit marked as coming soon. FreeAgent is not listed, which matters for practices with many sole trader clients on that ledger.

Fathom is a reporting workhorse that includes three-way cash flow forecasting, budgets and multi-currency consolidations on its Pro plan. Its Portfolio plan is aimed at firms that want oversight across a large client base at a low cost per company. The directory verdict describes its AI commentary as genuinely useful rather than bolted on.

Syft Analytics is strongest on presentation and benchmarking. Xero announced in September 2024 that it would acquire Syft for up to US$70 million, so practices standardised on Xero can expect tighter integration over time.

Xero Analytics Plus is not a separate purchase in the UK; the forecast comes with the plan. It is covered in more detail below.

Datarails is a different class of tool: an Excel-native FP&A platform with forecasting inside. It fits a practice supporting a mid-sized client with its own finance team rather than a portfolio of small businesses.

If the problem is less about forecasting and more about getting paid, a credit control tool such as Chaser, which holds an editor score of 4.8 out of 5, works on the receivables that feed the forecast.

How much does cash flow forecasting software cost in the UK?

Pricing in this category is a mix of published GBP tiers, published foreign-currency tiers and quote-only enterprise contracts. Here is what the vendors publish.

Float lists three tiers, excluding VAT:

Essentials: £99 a month, or £79 a month billed annually, for businesses below £2m revenue.
Growth: £199 a month, or £159 a month billed annually, for businesses above £2m.
Scale: £295 a month, or £235 a month billed annually, for up to five entities, with additional entities charged on top.

Float offers a 14-day trial with no credit card required.

Fathom lists Pro at US$450 a month for 25 companies, with additional companies at US$17 each, and Portfolio from US$67 a month for 100 companies. Fathom says it supports billing in GBP, so confirm the sterling figure at sign-up. Both plans carry a 14-day free trial and no minimum contract.

Xero includes the forecast in its UK plans: Ignite at £18 a month, Grow at £39, Comprehensive at £55 and Ultimate at £70, all excluding VAT. Xero is currently running a six-month introductory discount for new UK customers.

Datarails and LiveFlow do not publish prices. The directory notes that LiveFlow's pricing is tailored to requirements and quoted after a demo, scaling with entities and seats.

Pro Tip: Price per client, not per subscription. A practice running forecasts for 20 clients will pay very differently on a per-entity tool than on a portfolio plan. Model your actual client count before booking demos.

Is the Xero built-in forecast enough?

For many small clients, it is a reasonable starting point. Xero's UK pricing page lists a 30-day cash flow forecast on Ignite, 60 days on Grow, 90 days on Comprehensive and 180 days on Ultimate. KPI and ratio analysis and industry benchmarking sit on Ultimate.

The directory verdict on Xero Analytics Plus sums it up: a convenient, good-enough short-term cash forecast if you live in Xero, best paired with a dedicated app for real planning.

The built-in forecast is likely to be enough when:

The client's main question is "will I be able to pay the VAT and payroll next month?"
The client has simple, regular income and few large one-off items.
You want a forecast at no extra software cost.

A dedicated tool earns its place when:

The client needs scenarios, such as a new hire, a new premises lease or a loan.
The horizon must run 12 months or longer, for a lender or investor.
The client has several entities that need a combined view.
You want to present forecasts alongside management accounts in a single branded pack.

How do you roll out forecasting across a client base?

Rolling forecasting out to a whole client list at once usually fails. A staged approach works better.

Pick five pilot clients. Choose clients on a supported ledger, with reasonably clean bank reconciliations and a known cash concern. Forecasts built on unreconciled data are wrong from day one.
Clean the inputs. Check that open invoices and bills are accurate, that old unpaid items are written off or chased, and that recurring costs are coded consistently. Our guide to bank reconciliation software covers the reconciliation side.
Set realistic payment assumptions. Replace invoice due dates with each major customer's actual payment behaviour. If a customer on 30-day terms routinely pays in 55 days, the forecast should say 55.
Add the tax calendar. Put VAT, PAYE and corporation tax payments in as fixed outflows.
Review monthly with the client. Compare last month's forecast with what actually happened, explain the variance and adjust the assumptions.
Package and price it. Once the pilot runs smoothly for two or three cycles, turn it into a fixed-fee advisory service and extend it to the next group of clients.

Pro Tip: Keep a simple variance record for each client: forecast closing cash versus actual closing cash each month. It is the fastest way to prove the service is working, and the fastest way to find a bad assumption.

Why does independent evidence matter when choosing cash flow forecasting software?

Every vendor in this category describes its forecasts as accurate and its AI as intelligent. Those claims are hard to test in a 14-day trial, especially when the trial runs on demonstration data rather than a real client's messy ledger.

Independent editor scores give a starting point that does not come from the vendor's marketing team. A last-verified date tells you when someone last checked the pricing and features, which matters in a category where prices change often; Xero, for example, has announced US price rises from 1 October 2026. The AI Ledger directory records both for every listed tool, and scores are not affected by any commercial relationship.

Use those scores to build a shortlist, then test the shortlisted tools on two or three real clients. That combination, independent screening followed by your own trial on your own data, is more reliable than either a vendor demo or a review on its own.

Realistic expectations: what a forecast can and cannot tell you

A cash flow forecast is only as good as its payment assumptions, and those are usually the weakest part. Treat the software as a way to keep a forecast current, not as a way to predict when customers will pay.

No tool on this list can know that a key customer is about to go into administration, or that a client is planning to buy a van without telling you. Forecasting software is very good at arithmetic and at keeping data fresh. The judgement about what will actually happen still sits with the accountant and the client, and the monthly conversation about variances is where most of the value lies.

Find your next cash flow forecasting tool through The AI Ledger

The reporting and dashboards category lists every forecasting and reporting tool in the directory, with editor scores, pricing summaries and last-verified dates. If you are not sure where to start, the AI Ledger finder narrows the list by practice size, ledger and budget, and the comparison tool puts two or three options side by side.