Agent authorisations, client UTRs and every client’s filing history.
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For accountants · Switching
Switching your Self Assessment software
Move clients across one tax year at a time, including earlier years they still owe. Agent authorisations stay with you at HMRC, returns your old software already filed stay there, and nothing is charged until you file.
- No data migration
- Authorisations unaffected
- Earlier years filed too
- Prepare free
Old software
- Returns it already filed
- PDFs and computations
- Amendments to its returns
HMRCAgent authorisations stay with you
Self Assessment Software
- Current and earlier tax years
- Late and missed returns
- Team, approvals and filing
0client re-authorisations needed
1 loginsaved once for the whole practice
1 creditper client per tax year you file
7 figuresto bring forward per client
In short
Switching software changes nothing at HMRC: agent authorisations belong to your agent credentials, not to the program you file from. File this year’s returns here, and any earlier years a client still owes. Returns your old software already filed stay there, so export them as PDFs. The first return here needs a few figures from the return before it, such as losses, capital allowance pools and payments on account.
This page covers
- What moves, what stays and when to switch
- Filing earlier years a client still owes
- The figures to bring forward
The basics
What moves and what stays
Returns it has already filed, and any amendments to them. Export the PDFs before your licence ends.
Every return still to file, this year or earlier, plus your team, client approvals and amendments to returns filed here.
How to switch
Switch in four steps
01 Step 1 of 4
Register the practice and save your agent login
Practice admin
Create a practice organisation, then open HMRC details and save your agent Government Gateway user ID and password once. It is used when you file, never to sign in.
Clients with their own Gateway login saved on their details file with that instead. Partnership returns always use the practice login.
In the appHMRC details → Save HMRC login
02 Step 2 of 4
Add clients and open the year they owe
Add clients as their records arrive, then open the tax year that needs filing. That can be this year’s return or an earlier one the client never sent.
Add the Gateway login only for clients you file with their own credentials. Everyone else files under the practice login.
In the appClients → Add client
Good to know
- Keep a list of who has moved and which years each client still owes.
03 Step 3 of 4
Bring forward figures from the return before
The first return you file here for a client needs a few figures from the return before it: losses, capital allowance pools, unused finance costs and payments on account.
That is true whichever tax year you start with. Use the PDFs from your old software, or the return you have just filed here for the year before.
SourceThe previous year’s return
04 Step 4 of 4
File earliest first, then watch the results
Where a client owes more than one year, file the earliest first so each return has the right figures to carry into the next. Check the first few calculations against the client’s history before approval.
Once HMRC accepts a return, the filing log records who sent it. From then on, work the season from My Returns.
In the appMy Returns
Earlier years
Returns from earlier tax years
New clients often arrive with a year or two still unfiled. You do not need the old software to catch them up.
| Situation | What to do here |
|---|---|
| Client never filed last year | Open that tax year on the client, prepare it and file it here |
| Client owes several years | File each year as its own return, earliest first |
| Return filed here needs correcting | Start amendment on the filing desk, then resubmit |
| Return filed by your old software needs correcting | Amend it in that software or with HMRC directly |
| What it costs | One credit for each client and tax year you file |
HMRC’s late filing penalties and interest depend on the dates, not on the software you file from.
Bring forward
Figures to bring over from the return before
The first return you file here for a client, whichever tax year it is, needs some figures from the return before it.
| Figure | Where to find it on the earlier return | Where it goes here |
|---|---|---|
| Trading losses brought forward | SA103 loss to carry forward | SA103 losses section |
| Capital allowance pools | The capital allowances computation | SA103 capital allowances |
| UK property losses brought forward | SA105 loss to carry forward | All your UK property block |
| Unused finance costs | SA105 unused residential finance costs | All your UK property block |
| Capital losses brought forward | SA108 losses available to carry forward | SA108 |
| Payments on account already made | HMRC statement or the earlier SA110 | SA110 and the payment note |
| Student loan plan type | Payslip or Student Loans Company letter | SA100 student loan questions |
Timing
When to switch
- 1April to June
The cleanest start: open the new tax year here and clear any earlier years clients still owe.
- 2Summer
Move simple returns while the season is quiet.
- 3Autumn
New clients start here, with any missed years filed first.
- 4January
Do not move a return halfway through. Finish anything started elsewhere there and file the next one here.
Checklist
The switching checklist
Before you move
- Export PDFs of every filed return and computation
- Note each client’s losses and pools
- List any earlier years each client still owes
- Check when your old licence ends
After you move
- Save the agent login under HMRC details
- Invite the team with the right roles
- File outstanding earlier years first, earliest year first
- Keep the old software’s PDFs for returns it filed
FAQs
Common questions
Do I need to re-authorise clients with HMRC when I switch software?
No. Agent authorisation is between you and HMRC. It does not depend on which software you file from.
A client owes several years. Which should I file first?
The earliest. Losses, capital allowance pools and payments on account flow from one year into the next, so each return needs the one before it settled.
Can I import clients from my old software?
Not today. Add each client as you start their return. Most practices move clients over during the year rather than in one go.
Can I file an earlier tax year’s return here?
Yes. Open the tax year on the client, prepare the return and file it to HMRC. Each client and tax year you file uses one credit.
Can I amend a return filed in my old software?
Amend it in the software that filed it, or with HMRC directly. Returns filed here are amended here with Start amendment on the filing desk.
Does it cost anything to try?
No. Prepare as many returns as you like for free. A credit is used only when you file.
Keep going
Prepare free
Move your first client this week.
Register the practice, save your agent login and prepare one return free, this year or an earlier one.