Client frequently paying late. Manager claiming I make mistakes but doesn't prov...

I work for a small managed service provider. The owner is almost always late paying my invoices and I usually remind him a couple times. In addition to the invoices, he requested I fill out time sheets in the proprietary system he built. Recently he said that my invoice doesn't match the time sheets so he fixed the time sheets for me but won't do this again. I'm not sure what the mistakes were but I actually copy the data from the time sheets to my invoices. What should I do to have him pay on time? Some of my ideas are

1. tell him that he has a certain number of days to point out any errors/inconsistencies but he can't withhold payment for over a week without saying anything
2. charge a late fee for late payments
3. suggest that we only use invoice or time sheets as they seem redundant
4. suggest I can test and fix bugs in the time sheet system he made
5. suggest that if something looks wrong or is inconsistent, he sends me a screenshot and documentation

I've actually noticed a bit of a pattern of him claiming I made a mistake and when I provide him evidence I didn't, he drops the subject but doesn't concede. Another time he told me he reset a password that I needed to use. He said he recorded the new password in a particular system. This system was big and I sent him screen shots of all the logical places I thought he would have saved it. I don't think he even looked at my screenshots and just told me it was there in the same place I sent him a screenshot of. Finally he sent me a screenshot with the password in the system, I think he has a view that is different than mine when logged in. I had already messaged him that this may the what was happening and he just didn't respond to this comment, and it seems to me this is an unresolved technical issue.

I spent 10 years as an independent contractor working direct with clients (no recruitment agency in between) and chasing them to pay is unfortunately sometimes just part of the work you have to do.

Most clients (even smaller ones) will pay on time but every now and then you get one who just seems to have an excuse every time you remind them - at that point you have to decide how much you need their income stream, and whether it’s worth the hoops you have to jump through to keep it.

In your case, I’d simply submit your invoice and attach a copy of your own timesheet and a copy of the client’s timesheet (use the printscreen key if you can’t print to pdf). Then, if they complain the timesheet is wrong you can ask them which bit is wrong on the copy of their timesheet that you included with your invoice.

And review any late payment terms in your contract - you can’t suddenly add terms unless they agree to them. Luckily, in the UK there’s a statutory law called the “Late Payment of Commercial Debts (Interest) Act 1998” which lets small businesses charge the Bank of England base interest rate plus 8% on debts older than 60 days. You don’t even need a reference to this in your contract as it’s a statutory law - I only ever had to gently mention once in 10 years that I’d be charging interest from date xx/xx/xxxx and the name of the Act, and the invoice was paid the next day.

However, even if you fix the timesheet problem, be prepared for another smokescreen - the sort of person who quibbles repeatedly over timesheets is certainly going to have other delaying tactics up their sleeve.

Ultimately if you’re losing a lot of income because you’re chasing payments from one client rather than working billable hours, have a think to yourself about whether they’re worth the hassle of doing business with…