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mbtaxoffice@gmail.com

Now booking new clients for Spring 2026 · Limited slots
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CIS Specialists · Construction Industry Scheme

CIS done right — every subby, every month.

Verify subcontractors, file the CIS300, reclaim the 20% you suffered. We run construction payrolls for contractors and subbies across the UK — without the spreadsheet meltdown.

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Who we help
1,400+
Subbies on our books
£1.8m
CIS reclaimed for clients
19th
Filing deadline · met 100%
Who we help

Two sides of the same job.We do both.

Whether you’re the one paying out or the one being paid, CIS rules apply — and the paperwork is different. We handle both ends fluently.

Payroll Services

Builders, civil engineers, scaffolders, electrical contractors — anyone hiring labour-only or supply-and-fit subbies under CIS.
  • Verify every subby against HMRC before first payment
  • Calculate & apply correct deduction (0%, 20%, 30%)
  • Issue Payment & Deduction Statements every month
  • File the CIS300 by the 19th — no fines, ever
  • Handle disputes & HMRC queries on your behalf
From£35/mo
Get a quote

You get paid by contractors

Sole-trader trades, labour-only builders, limited-company subbies — paid net of CIS and chasing every penny back.

  • Register you for CIS & get the deduction rate down to 20%
  • Apply for gross payment status when you qualify
  • File your Self Assessment claiming all CIS suffered
  • Chase your tax rebate from HMRC — typically £2k–£8kr
  • Maximise allowable expenses (tools, mileage, PPE, training)
From£195/yr
Get a quote
By the numbers

Twenty-five years of receipts.

We’ve built our practice around the things bigger firms keep cutting — phone calls, fixed prices, and people who actually know your file.
Gross status
0 %

For subbies that pass HMRC’s turnover, compliance & business tests. Paid in full, no CIS withheld.

Standard rate

20 %

Default for subcontractors verified and registered with HMRC for CIS. Most common.

Higher rate

30 %

Applied when a subby is not registered or can’t be verified. We get this fixed fast.

What’s included

Every payslip, filing and form —handled.

From the first verification to the year-end rebate, every CIS task is covered. No extra invoice for “complications”.
Subcontractor verification
We verify every subby against HMRC before their first payment so the right deduction is applied from day one.
Real-time HMRC check
Monthly CIS300
Filed with HMRC by the 19th of every month, every month. Gross, deductions and “nil” returns when nothing was paid.
Filed by the 19th
Payment statements
Every subcontractor gets a Payment & Deduction Statement within 14 days. Branded, emailed, archived — your audit trail.
Within 14 days
Gross status applications
For subbies hitting the £30k turnover and compliance thresholds, we apply for gross status — so they keep 100% of every invoice.
Apply & appeal
CIS suffered / rebates
For subcontractors: we tally every penny of CIS deducted, claim it on your Self Assessment and chase HMRC for the rebate.
Avg. £2k–£8k back
HMRC enquiries & appeals
Wrong rate applied? Penalty notice? Verification stuck? We pick up the phone to HMRC so you don’t have to.
We deal with HMRC
Our process

From first sub to filed return — in 4 steps.

Same rhythm every month. You’ll always know what’s coming and when.

Onboard & verify
Send us your subbies’ names, UTRs and NIs. We verify each one with HMRC and confirm the right rate.
Day 1–2
Log payments
You send us invoice values weekly or monthly. We log them, calculate the deduction and prepare the statements.
Every payment
File CIS300
Filed with HMRC by the 19th. You get a copy plus the exact figure to pay over. No surprises, no late penalties.
By the 19th
Reclaim & review

For subbies: we file your SA, claim back all CIS suffered, and chase the rebate. Year-end review for contractors too.

Year-end

Why specialists matter

Generic accountants miss CIS-shaped things.

CIS has its own rules, deadlines and language. We’ve been doing it for 25 years — here’s the difference it makes.

General firm

Treats CIS as "just another return"

  • Forgets to verify subbies before first payment
  • Misses the gross-status threshold — you keep losing 20%
  • Late CIS300 = £100 fine per month (compounding)
  • Charges extra for "complex" returns and HMRC calls
  • Forgets CIS suffered on the subby's SA return
M&B Tax Services

You get paid by contractors

  • Verification done before the first invoice gets paid
  • We watch turnover — apply for gross status when you qualify
  • 100% on-time filing record — 25 years, no fines
  • Fixed monthly fee. HMRC calls included. No surprises
  • Every penny of CIS suffered claimed back — typically £2k–£8k

FAQ

CIS: common questions..

Quick answers to what most contractors and subbies ask before signing up. Anything else? Phone us.
What's the CIS300 and when is it due?

The CIS300 is a monthly return contractors must file with HMRC listing every subcontractor paid, the gross amount and any deduction taken. It’s due by the 19th of the month following the tax month (so May payments → return due 19 June). Late filing is an automatic £100 penalty, rising each month. We file every single one of our clients’ returns on time.

Typically £2,000 to £8,000 for a sole-trader subby earning between £25k and £55k, depending on allowable expenses (tools, fuel, mileage, PPE, training, accountancy). We claim everything legally allowable. Most rebates land within 4–8 weeks of filing your Self Assessment.

If your turnover (excluding materials) is over £30,000 for sole traders (or £30k per partner / director) and you’ve kept your tax affairs clean for 12 months, yes — definitely. Gross status means contractors pay you in full with no CIS deducted, so your cashflow improves dramatically. We handle the application and any HMRC pushback.

You must deduct CIS at the higher 30% rate until they register and we can re-verify them. We chase the subby, help them register (often same day), and get them switched to 20% — usually within a week. The over-deducted amount gets reclaimed via their Self Assessment.

Yes. CIS is only deducted on the labour element, not on materials — so an invoice for £5,000 (£3,000 labour + £2,000 materials) only attracts CIS on £3,000. Most generalist firms get this wrong. We extract the split from every invoice and apply CIS correctly.

Absolutely — most of our new contractor clients come mid-year. We collect your prior CIS300s, subby data, HMRC agent authorisation and reclaim history. First return out by the next 19th deadline, no gap. Email mbtaxoffice@gmail.com to start.
Let's talk CIS

Reclaim what's yours.

Book a free 30-minute call. We’ll size up the rebate or scope your CIS300 setup on the spot — and tell you what we’d charge.

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Pay Online
  • Free initial call
  • Fixed monthly fee
  • 25 years of CIS