Outsourced Self Assessment Returns for UK Accounting Practices
SA100 compliant self assessment returns delivered in 5 working days, reviewer ready, senior tax reviewed, and packaged for clean client sign off.
Built for UK Accounting Practices of Every Size.
Whether you're managing a January backlog, covering a staff gap, or scaling through peak season, our self assessment service slots directly into your existing workflow.
Solo & Small Practices
- Affordable per return pricing, no retainer
- No minimum volume commitment
- Same 5 day turnaround from day one
- Works in your existing software
Growing Firms
- Scale instantly at peak (Jan 31st & July 31st)
- No permanent headcount required
- Dedicated account contact for your firm
- Senior tax reviewed output every return
Mid Size & Multi Office Groups
- High volume capacity on demand
- Consistent return standards across offices
- Monthly volume reporting & SLA tracking
- Complex cases: CGT, foreign income, trusts
Everything Covered,
SA100 to Submission.
From source documents to reviewer ready returns. We handle every stage of self assessment preparation so your team focuses on client relationships and sign off.
SA100 Return Preparation
- SA100 core return with all required supplementary pages
- SA103 (sole trader) & SA105 (property income)
- SA106 (foreign income) & SA108 (capital gains)
- SA102 employment income schedules
Source Document Organisation
- Structured handling of client-supplied records
- Income and expense categorisation schedules
- Rental income reconciliations and schedules
- Investment and dividend income schedules
Tax Computations
- Multi-source income calculations
- Capital gains tax computations
- Pension contribution relief calculations
- Gift Aid carry back claims
Reviewer Ready Delivery
- Open point query logs for the reviewer
- Reviewer handover notes with sign-off checklist
- Version controlled file delivery
- Revisions and amendments included
Your clients' software.
Our team knows it.
No onboarding friction. No tool switching. We step straight into the software your practice already runs on and get to work from day one.
Talk to our team
Outsource: But Why?
Because your senior team's time is worth more than return preparation. Here's exactly what you gain.
Focus on Client Relationships
Free your senior team from return preparation. Spend that time on tax planning, client conversations, and growing your advisory practice.
Save Up to 50% in Costs
Eliminate the overhead of a full time tax technician. Pay only for the returns you need, with no salaries, NI, or desk space during quiet months.
Expert Tax Team on Every Return
Senior qualified reviewers check every return before delivery. You receive reviewer ready output, not a draft that needs significant rework.
No Software Migration
We work directly inside IRIS, TaxCalc, CCH, or Capium from day one. Your workflow, your templates, your review process, unchanged.
Flexible Peak Capacity
Instantly add self assessment resource during the January 31st and July 31st deadlines. Scale back when the pressure eases. No permanent commitment.
Six Reasons UK Firms Choose Us for Self Assessment.
Expert reviewed output, guaranteed turnaround, and seamless software compatibility, from the only outsourcing partner built specifically for UK accounting practices.
Up to 50% cost saving
Reduce return preparation cost compared to equivalent UK senior staff, without sacrificing quality or review oversight.
5 day turnaround
Consistent delivery in 5 working days from receipt of source documents, even during January and July peak periods.
HMRC compliant returns
All returns prepared to HMRC standards. SA100 with all required supplementary pages, accurate computations, and structured query logs.
Senior tax reviewed output
Every return is quality checked by a qualified tax professional before delivery, and you receive reviewer ready work.
Scalable peak capacity
Add self assessment resource instantly during January and July deadline periods. No permanent headcount and no minimum volume.
GDPR secure delivery
NDA signed before work begins. Encrypted file transfer, role based access controls, and full GDPR compliance throughout.
How It Works
Share Source Documents
Secure file upload via our portal
Return Preparation
Prepared by qualified tax professionals
Senior Tax Review
Reviewed by an experienced senior tax professional
Quality Check
Multi-level quality assurance
Client Ready Delivery
Delivered in 5 working days, ready for client sign off
"Probal Global transformed our self assessment season. We went from working weekends in December and January to delivering every return on time with capacity to spare. The returns arrive clean, the query logs are thorough, and our team can actually focus on the clients rather than staring at spreadsheets."
£35k+
Annual saving in staffing costs
Probal Global vs. Your Other Options.
See why UK practices choose dedicated outsourcing over in house preparation or ad hoc freelancers.
Real questions from UK accountancy practices answered honestly.
If you're considering bringing in external support for your construction clients, you probably have a few questions. Here are the ones we get asked most, with straight answers.
Still have questions? Get in touchYes. We work directly inside your existing tax software so there is no migration and no change to your internal review workflow. We adapt to your templates and file structures from day one.
We support all SA supplementary pages including SA102 (employment), SA103 (self-employment), SA105 (property), SA106 (foreign income), SA108 (capital gains), and SA109 (residence). We handle mixed income profiles and complex cases.
Capacity scales instantly. Most firms add dedicated self assessment resource from us in November through January. Work is allocated the same day it arrives and turnaround is maintained at 5 working days throughout peak.
We sign an NDA and DPA before any work begins. All files are transferred via encrypted channels. No client data is stored after delivery. We are GDPR registered and ISO 27001 aligned.
Yes. We log gaps early and return structured query logs so your client-facing team can resolve issues before deadlines tighten. This reduces review friction and last-minute chasing.
Revisions based on reviewer feedback are included at no extra charge. We aim to turn around revision files within 24 hours.
Free Trial Available
Try Probal Self Assessment Free.
10 Hours, No Cost, No Commitment.
Send us a real client file. We'll prepare the return in your software, return a reviewer ready file in 5 days, and let the quality speak for itself.