Timing of SIPP contributions for freelancer?

A question about : Timing of SIPP contributions for freelancer?

I work freelance but usually know a few months in advance what my invoices will be. I pay the full amount of my earnings into my SIPP each year (accounting for the government's tax relief being added). Can I pay into this year's SIPP now on the assumption my invoices will be what I expect or do I have to wait until I have sent out those invoices?

Ultimately, what if I did pay into the SIPP now and then wasn't able to invoice for Feb and Mar for whatever reason? Would I be penalised for paying more into the SIPP that I earned in the tax year (and claiming the government's tax relief) or would it be sorted out in my tax return?

Best answers:

• Could you not make some small "pilot" contribution now, and then phone at the last minute and make the balance of your contribution using your debit card?
• Thanks for the replies - my work very part-time so no company set up. Will probably just wait until after end of the tax year and do them to keep it simple.