Overpaid Employer's NI via Umbrella - how do I get it back?

[lucyclarityumbrella]

As Eek said unfortunately.

[eek]

NI is calculated and paid on weekly / monthly basis* - there is nothing to reclaims you haven't been over taxed

*this is only not true for directors of companies which is why you may be confused.

[gizzmo]

Hi

I'm new to working through an Umbrella - I started an assignment in January of this year - the current contract is for 6 months - straddling 2 tax years.
Prior to starting this role I had taken some time out, so for the tax year 2020/21 I only had 2 monthly salary payments - in Feb and March.

When the Umbrella worked out my payments, they used the monthly allowances for Income Tax, Employers NI and Employees NI before deducting the respective Income Tax and NI on the remainder.

I utilised salary sacrifice to maximise my contributions to my SIPP and reduce my taxable salary, So for the tax year 2020/21 - my total gross pay only amounted to just under £3,000 for the entire tax year.
This is well under the annual allowances for Income tax, Employers NI and Employees NI.

Now I know I can claim back the overpaid Income tax via my self-assessment, and I found a procedure to claim back my overpaid Employees NI on the gov.uk website.
But how would I claim back the overpaid Employers NI?
Is this process something that Umbrellas would be familiar with and would it happen normally via the payroll, or do I need to ask them to claim it back from HMRC and then pay it back to me?

Is there a "normal" Umbrella process for employees that have deductions made based on monthly allowances but then don't work for the entire 12-month tax year so don't exceed the annual allowances?

In the event I don't extend my contract, and do not take another one, i will have a similar situation in 2021/22 as well

Hoping for some guidance from the Umbrella experts on here (Lucy, eek etc) - thanks in advance.
gizz