With ever changing legislation IR35 can be a minefield for those working inside and outside contracts, but we've simplified this below.
The short answer is no, IR35 rules are irrelevant for those being paid their income via an umbrella company. You can work inside or outside IR35, and your deductions would be the same via the umbrella.
As the umbrella company acts as an employer, all income is treated as employment income, and all tax and NI contributions are deducted at source, by us. This means IR35 is not applicable and no separate declaration needs to be made to HMRC. All income is reported via RTI with each payroll, and HMRC will be informed of your deductions.
If you have a contract that is outside IR35 and would like to look at LTD company options just get in touch with your Account Manager at Nasa and they'd be happy to talk you through this.